Do Roof Rejuvenation Treatments Like Roof Maxx Really Work?

Introduction

Several spray-on “asphalt shingle rejuvenator” products have hit the roofing market in the past several years, promising to extend the life of aging roofs at a fraction of the cost of replacement. These asphalt shingle roof rejuvenation products are often marketed as miracle solutions: restoring oils in dried-out shingles, reviving flexibility, stopping granule loss, and adding years of service life. I wanted to know if these roof treatments actually do any good at all.

I’m a roof consultant, so it’s my job to have well-informed opinions about roofing products, among other things. But when a friend of mine asked me what I thought about a particular roof treatment product, I had to tell him I didn’t know enough about it to have an opinion. I decided to do some research and form an opinion so I could give him a better answer.

I used AI to gather all the information about roof rejuvenation products available on the internet and went through all the marketing claims, the available independent data, a lot of anecdotal evidence, and any relevant roofing industry articles and technical bulletins (almost non-existent). I filtered all of this information through my own common sense and roofing knowledge (from years of studying and researching roofing products and over 25 years of practical experience in the roofing industry). I put this article together as a way of answering my friend’s question. This article is basically my current opinion on the matter.

We’re going to take a critical look at asphalt shingle rejuvenation products. We’ll examine what these sprays are made of, how they are supposed to work, what major roofing manufacturers and industry experts say, and what independent tests (if any) reveal about their effectiveness. We’ll also look at possible drawbacks, from questionable longevity claims and warranty issues to fire safety and code compliance concerns. For homeowners, I’ll provide some guidance on what questions to ask treatment salesmen and whether these treatments are really appropriate for your particular roof. The goal here is an evidence-backed analysis that cuts through marketing claims to find out the truth about roof restoration treatments.

This article is focused on asphalt shingle “rejuvenation” treatment products, not traditional roof coatings. If you’re interested in regular roof coatings, I do have something to say about using roof coatings to extend roof service life here.

Nature of Asphalt Shingle “Rejuvenation” Products

What Are These Products Made Of?

Asphalt shingle rejuvenators are typically spray-applied liquids (sometimes marketed as “resealers”, “resaturants”, or “roof restoration treatments”) designed to penetrate into the shingle. Most roof rejuvenation products today use plant-based oils, especially soybean oil derivatives, as their active ingredient. For example, Roof Maxx (one of the leading brands) is a soy methyl ester-based emulsion, essentially processed soybean oil in water​. Other brands like Greener Shingles, Roof Rejuvenate, Ugly Roof, and Peak 301 similarly use bio-based oils (often soy oil or other fatty acids) as the main rejuvenating agent​. These oils are often emulsified with surfactants and stabilizers to help them spread and absorb into the asphalt. The emphasis on natural, non-toxic ingredients is a selling point – many are marketed as environmentally friendly. Roof Maxx, for example, is 86% USDA certified biobased content​ and safe for people, pets, and plants.

It’s worth noting that asphalt rejuvenation does have a respectable track record: it has its roots in the pavement industry. For decades, highway departments have used rejuvenator sprays on asphalt roads and parking lots to extend pavement life. Asphalt pavement products typically contain petroleum-derived oils or maltenes (the oily fractions that asphalt loses as it oxidizes​ over time). Today’s roof rejuvenators essentially try to adapt that concept to asphalt roof shingles, substituting plant oils for petroleum in many cases to reduce odor and environmental impact​. In both cases, the goal is the same: replenish the lost “flexible” components of aged asphalt.

How Are They Supposed to Work?

Asphalt shingles today are made with a fiberglass felt reinforcement mat saturated and coated with asphalt binder and surfaced with mineral granules. The asphalt part is the waterproofing component of the shingle and provides most of its mass. When new, the asphalt is rich in pliable oils (sometimes called maltenes) that keep the shingle flexible and help bond the granules to the shingle’s surface. Over time (typically noticeable after 10+ years of exposure), heat, UV radiation, and exposure to the air cause the asphalt to oxidize and “dry out” – the lighter oils evaporate away or convert into harder, brittle molecules (asphaltenes). This leads to brittle, shrunken shingles with reduced flexibility. You may see signs like curling edges, cracking, or excessive granule loss as the shingles age.

Rejuvenation products aim to reverse or slow this aging process by adding oil back into the asphalt. The theoretical mechanism: the oils soak into the shingle and “re-saturate” the dried asphalt, somewhat like adding oil to a dried-out leather. This infusion is said to restore the chemical balance of the asphalt, replacing maltenes and reducing the asphaltene fraction percentage, thereby softening the asphalt binder​.

In terms of practical effects on the shingles, a rejuvenator is supposed to make a brittle shingle more flexible, able to bend without breaking, which decreases the risk of wind damage, and more sticky/resilient, improving the adhesion of the protective granules, which reduces the risk of UV damage. One manufacturer describes it as “restoring oils to the shingle that have been lost to evaporation; and in doing so we restore the shingle’s flexibility, the granule adhesion and waterproofing of the shingle material.”​ The treatment is like a “moisturizer” for the dried asphalt: the shingle should regain some of the pliability it had when it was newer, extending its life.

Many rejuvenators also claim ancillary benefits. Because they are oil-based and hydrophobic, they can increase water resistance – potentially helping seal very small cracks. Some advertise that they reduce shingle permeability by filling micro-pores (though as we will see in test data, treated shingles still transmit moisture vapor, just less). Some products add algaecides or UV-reflective components, but the primary function is still the oil replenishment.

It’s important to distinguish penetrating rejuvenators from film-forming coatings. Rejuvenators like Roof Maxx, Greener Shingles, etc., are typically designed to soak in and not leave significant surface residue (they often dry clear with no paint-like surface layer). In contrast, standard roof coatings (like silicone, acrylic, or latex “roof paints”) create a new surface layer on the shingle. These coatings might change the roof color or add reflectivity, but they are not “re-saturating” the asphalt. And the Asphalt Roofing Manufacturers Association (ARMA) strongly warns against field-applied coatings on shingles (more on that later)​. The products marketed as shingle rejuvenators are almost all penetrating oils rather than surface coatings.

Scientific Theory vs. Marketing Hype

The purported science behind asphalt rejuvenation is plausible and borrows from proven practices in asphalt pavement maintenance. Adding oils can indeed make oxidized asphalt softer and more pliable – this is something that can be measured in a lab with standard asphalt tests. The key questions are how well this works on a shingle roof in the real world, and for how long. The rejuvenation product manufacturers often make bold claims, so it’s important to check those claims against the available data:

• “Restores flexibility”: This is one of the main claims. If true, a treated shingle should bend without cracking, like a newer shingle. We will examine test data below to see if shingles become more flexible after treatment.
• “Extends roof life 5 – 15 years”: Many marketing materials promise that a treatment can add 5 years of life per application (with the option of retreating every 5 years, up to three treatments)​. Roof Maxx, for example, advertises up to 15 extra years if you do three treatments over time​. This is a big claim. We’ll look for evidence as to whether this holds up.
• “Rejuvenates waterproofing”: Some companies imply their product can stop minor leaks or at least prevent them by sealing the shingle. We need to see if there is any proof or if leaks usually stem from other issues (flashings, etc.) beyond what an oil could fix.
• “Improves granule adhesion”: If oil truly restores shingles’ ability to hold granules, the granules should stick better and fewer wash off into gutters after treatment. There are standardized tests for granule loss we can check for treated vs. untreated shingles.
• Other claims: increased hail impact resistance, lower insurance costs, improved fire resistance.

In the following sections, we’ll review the limited available test data and some anecdotes, apply some common sense, and see what conclusions we can draw. But first, let’s see where the roofing industry and shingle manufacturers stand on the use of these products.

Industry & Manufacturer Positions

Understanding industry and manufacturer positions on asphalt rejuvenation treatments requires first clarifying the difference between traditional “roof coatings” and “roof rejuvenation treatments”:

Roof Coatings vs. Roof Treatments: Clarifying the Difference

• Roof Coatings: These products typically form a visible, barrier film on top of shingles. Common materials include acrylic, silicone, or elastomeric coatings, often marketed for UV reflection, waterproofing, or aesthetic improvements. Such coatings would effectively add a new surface layer on top of the existing shingles.
• Roof Rejuvenation Treatments: Rejuvenation treatments (such as Roof Maxx, Greener Shingles, Peak 301) are penetrating products designed specifically to soak into the shingles. They are usually bio-based and formulated to restore flexibility, enhance granule adhesion, and reduce brittleness without leaving any residual surface layer.

This distinction is important since the roofing industry’s stated positions on the subject are almost completely focused on traditional coatings (they’re against them when it comes to shingles), and they have very little to say about roof treatments (they have so far ignored them).

Asphalt Roofing Manufacturers Association (ARMA)

ARMA, representing major asphalt shingle manufacturers, explicitly cautions against field-applied coatings due to several potential issues:

• Fire Performance: Field-applied coatings can negatively affect a roof’s fire rating.
• Moisture Retention: Coatings might trap moisture within shingles or roof decking, potentially accelerating deterioration.
• Granule Adhesion: Some coatings may interfere with granule adhesion, leading to premature shingle wear.

ARMA’s primary concerns appear directed at traditional film-forming roof coatings, especially those creating impermeable surface layers. Note that ARMA does not differentiate between coatings and rejuvenation treatments in their published bulletin; they broadly advise caution against any field-applied coating, leaving ambiguity about their stance on penetrating rejuvenation products. The roofing industry currently seems to lack a specific endorsement or clear rejection explicitly for rejuvenation treatments.

National Roofing Contractors Association (NRCA)

The NRCA echoes ARMA’s general caution regarding field-applied roof coatings. While NRCA has not officially addressed rejuvenation treatments in their formal statements, the association typically refers directly to ARMA guidance and emphasizes skepticism about the long-term, proven effectiveness of any post-installation topical treatment. Informal commentary from NRCA members in trade publications has indicated a cautious approach towards rejuvenation treatments, primarily due to limited long-term performance data, rather than outright disapproval.

NRCA’s publications stress proven maintenance practices (routine inspection, replacing damaged shingles) over rejuvenation sprays or coatings. NRCA’s advice in Professional Roofing magazine has highlighted concerns regarding warranty voidance and moisture trapping from unapproved coatings.

Shingle Manufacturers (GAF, Owens Corning, CertainTeed)

Individual manufacturers (GAF, Owens Corning, CertainTeed, etc.) typically mirror ARMA’s guidance. Individual shingle manufacturers often caution against or directly prohibit traditional roof coatings, clearly stating that such products can void warranties and disrupt performance characteristics of their shingles. Regarding rejuvenation treatments specifically, shingle manufacturers generally adopt a conservative stance:

• Warranty Implications: Many shingle manufacturers have warranty clauses broadly stating that any unapproved, aftermarket topical applications – coatings or otherwise – could void the warranty. They typically do not mention rejuvenation treatments, although they may mention coatings. Since these are really two different things, this creates ambiguity.
• Approval Status: No major shingle manufacturer currently endorses rejuvenation treatments officially or offers a rejuvenation product under their own brand. Their silence on specifically endorsing rejuvenation treatments, however, does not imply outright rejection but reflects caution and a lack of independent, long-term studies proving these treatments align with their performance standards.

If your roof is still under a manufacturer’s warranty period, using a rejuvenator may or may not risk that coverage. Many rejuvenation companies argue this is a non-issue: by the time a roof needs rejuvenation (say 10-15 years old), the shingle’s non-prorated warranty period is likely over, and any remaining warranty is prorated for material defects only. (You can learn more about roofing warranties here.)

Roof Maxx says that no warranty claim has been denied due to their treatment to date. “We have no indication that applying Roof Maxx will void or limit any shingle warranty – nor have we ever heard of a manufacturer’s warranty claim being denied because Roof Maxx was applied.”​ In 2024 on their Better Business Bureau page, they even offered to defend homeowners if a manufacturer were to deny a claim on that basis.​ Regardless, it’s wise to check your specific shingle warranty terms. Don’t expect a shingle maker to cover you if a treatment causes a problem.

It is telling that no major shingle manufacturer sells or endorses a rejuvenation spray for their own products. If it were a straightforward life-extender, you might expect manufacturers to offer “official” rejuvenation treatments as part of an extended maintenance program – but they don’t. Instead, this niche is filled by third-party startups and franchises. Manufacturers seem content to just sell you a new roof when the time comes.

International Institute of Building Enclosure Consultants (IIBEC)

IIBEC, formerly known as RCI, has yet to issue specific formal guidelines regarding rejuvenation treatments. Members have informally pointed out that, while the rejuvenation concept is scientifically plausible, there remains insufficient long-term field data to endorse such treatments fully. IIBEC members typically advise comprehensive roof management strategies rather than relying solely on treatments or coatings.

Insurance Companies

While not an “official” stance published in the way ARMA or building codes are, it’s worth noting how insurance companies might view these treatments. Typically, homeowners insurance is mainly concerned with the roof’s condition and age. Insurers often mandate roof replacement once a roof is beyond a certain age or if it’s in poor shape, to avoid future claims.

As of now, there is no widespread recognition by insurers that a rejuvenation treatment resets the clock on a roof’s age. In online discussions, homeowners have wondered if showing proof of a rejuvenation treatment would help with insurance (for instance, to prevent cancellation or to get better rates), but there’s no clear evidence insurers accept this. One user in a consumer forum noted their insurer simply wanted proof of a new roof or else would reduce coverage​.

There are anecdotal reports of insurers granting short-term extensions on roof age limits if a rejuvenation treatment is applied (like if an insurance company was about to cancel a policy because the 20-year-old roof needed replacement, a successful treatment and documentation might persuade them that the roof is sound for a few more years). Of course, results vary: this is not guaranteed and not all insurers will recognize rejuvenation. As a homeowner, you should inform your insurer if you treat the roof, especially if they have on record that the roof is old. Don’t assume it will lower your premiums (there’s little evidence of that), but it likely won’t raise them either. The main insurance benefit is avoiding the drastic step of non-renewal due to roof age in some cases​.

Insurance companies typically regard rejuvenation treatments as maintenance, not structural changes, and usually do not adjust coverage negatively. Some insurers may view treatments positively if they help prevent claims related to aging roofs. But don’t count on your insurance company giving you credit for a rejuvenated roof – at least not yet, while the technology is new and not code-sanctioned.

Summary of Industry Positions

The roofing industry’s official concerns (from ARMA, NRCA, and major shingle manufacturers) primarily target traditional film-forming roof coatings, explicitly warning against the potential negative impacts of these products.

Roof rejuvenation treatments, as penetrating, bio-based solutions, fall into a less clearly defined category, often being lumped into generalized cautionary language rather than explicitly addressed. The lack of direct endorsement or targeted criticism from industry bodies regarding rejuvenation treatments leaves homeowners in a grey area: rejuvenation treatments are neither officially recommended nor explicitly prohibited but are treated with caution due to very limited long-term performance data.

Effectiveness & Longevity Claims

Roof rejuvenation products are marketed with a variety of impressive claims. Common ones include:

• Extending Roof Life by 5 to 15 Years: As noted, many companies say each treatment adds about 5 years to the shingles’ life, and can be done multiple times. For instance, Roof Maxx advertises “up to 15 years of added life” with three treatments (one every 5 years)​. Competitors similarly claim a single application can delay the need for replacement by several years. This claim is perhaps the most appealing to homeowners.
• Improved Flexibility and Pliability: Marketing materials often show side-by-side comparisons of old brittle shingles vs. treated shingles that can bend without breaking. Roof Maxx cites an Ohio State University study on 17-year-old shingles, noting the treated shingles became significantly more flexible – able to pass the same ASTM pliability tests required of new shingles​. Restoring flexibility implies better resistance to cracking, thermal expansion/contraction, and wind uplift damage.
• Rejuvenated Waterproofing and Sealing of Small Cracks: The idea that a dry, porous shingle regains its water repellency is frequently mentioned. Some companies even suggest that very minor leaks or thin cracks in shingles might self-seal after treatment (though none would promise to fix an active leak around flashing, for example). By replenishing oils, the shingle surface becomes more hydrophobic, causing water to shed more easily rather than soak in.
• Granule Adhesion and UV Protection: Since granules are held in place by the asphalt, making that asphalt sticky again should reduce the loss of granules. Some claims include “up to 40-50% less granule loss” in testing. Granules protect shingles from UV rays, so keeping them on longer is directly tied to longevity. A treated shingle that holds its granules should deteriorate slower.
• Resistance to Hail and Wind Damage: A flexible, well-bonded shingle should, in theory, resist impact better (hailstones might bounce off without cracking the shingle) and resist wind uplift. Some rejuvenation brands tout that their treatment can improve a roof’s hail impact rating or at least make hail damage less severe. For wind, the logic is that if tabs are more flexible and the factory seal strips are softened, the shingles might reseal to each other better or at least not break in high winds.
• Cost Savings and Sustainability: These aren’t performance claims per se, but very heavily emphasized (this is practically the whole sales pitch): saving “80% of the cost of a replacement” (​Roof Maxx), preventing tons of waste from landfills, being “green” and using bio-based oil instead of petroleum, etc. Roof Maxx’s founders pitch their service as a way to curb the 11-13 million tons of shingle waste going to dumps annually​, which is a compelling point. They also note the convenience (done in hours, no mess or nails) and that it’s “like new roof performance at a fraction of the cost.”

Those are the claims – now what does independent data say? While truly independent (unaffiliated) research is very limited, we do have some third-party sources to examine. The two primary sources are:

1. Ohio State University (OSU) Technical Report (2017/2018): Conducted by researchers Juliana Vasco-Correa and Ajay Shah, this study evaluated Roof Maxx’s soy-based formula on 17-year-old shingles in a lab setting​. The tests were performed by PRI Construction Materials Technologies, a well-known independent lab that does a lot of ASTM testing for roofing products​. The OSU report and associated PRI data give insight into flexibility, granule loss, permeability, and other metrics before vs. after treatment.
2. PRI Laboratory Report for Greener Shingles (2018): Similarly, the company Greener Shingles commissioned PRI Asphalt Technologies to run screening tests on their rejuvenator (also soy-based) on old shingles​. That report (August 2018) provides quantitative results on flexibility, granule loss, hail impact, and fire spread for treated vs untreated samples​.

It’s worth noting that these studies were sponsored in connection with the product’s developers, so you have to consider the potential for bias. That said, the tests were conducted to recognized standards, and the data does support that the treatment had real effects on the material properties of aged shingles. These findings serve as initial scientific validation that rejuvenation can work on a physical level – at least in the short term.

What we don’t yet know from published research is how long those effects last in real-world conditions, and whether similar results would hold for different shingle brands, climates, and shingle ages. Lab tests under controlled conditions are one thing; true validation would come from documented performance over many years on a test population of actual roofs.

There have also been some field observations and demos (for example, a FOX 13 news report and a Minnesota Soybean Research & Promotion Council demo in Minnesota) and commentary from contractors both for and against the products. One roofing contractor, Able Roofing in Ohio, summarized results from “the study mentioned above” (likely referencing the OSU report or similar data) in a blog post. We’ll consider those perspectives as well.

Let’s look at each claim in more detail:

Flexibility and Pliability Restoration

One of the clearest pieces of evidence comes from the ASTM D3462 shingle pliability test. In this test, shingle samples are bent 90 degrees at room temperature (or sometimes colder) to see if the asphalt layer cracks. It’s essentially a pass/fail test – new shingles are supposed to pass without any cracking.

• In the OSU/Roof Maxx test, five samples of 17-year-old 3-tab shingles were tested for pliability before and after treatment. The result: untreated shingles failed in certain orientations, whereas Roof Maxx treated shingles all passed. Specifically, when bent “weather-side down” (which simulates wind uplifting a shingle), the untreated old shingles cracked in both machine direction (MD) and cross-machine direction (CMD), but the treated shingles did not crack at all. Both untreated and treated passed when bent “weather-side up” (not surprising, as that orientation is less stressful). This indicates a significant improvement in flexibility: shingles that would have broken when flexed now could flex without damage after the oil treatment. The OSU report concluded “Roof Maxx significantly improved the flexibility of the asphalt shingles” to the point of passing ASTM requirements​.
• The Greener Shingles PRI report similarly found improved flexibility. They used a low-temperature flexibility test at 23°C (73°F) where untreated samples had “fail” results (cracking) in some cases and treated ones passed. The summary stated “Flexibility @ 23°C was improved (Failure to pass).” While a bit confusingly worded, the data table shows treated shingles achieved higher flexibility values and passes. Essentially, the rejuvenator restored pliability that the aged shingles had lost.
• A homeowner or roofer might do a simple bend test on an old shingle: untreated, it snaps or creases, treated, it bends without damage. And anecdotal reports from dealers support this. One case study noted the shingles felt less brittle to the touch a few days after treatment, and could be bent slightly without the audible crackle you’d hear pre-treatment.

Implication: This data supports the claim that rejuvenation oils restore flexibility. This is important for longevity because as shingles become brittle, they are prone to crack under thermal movement or wind load. By making them supple again, they can better withstand weather stresses. But the important critical question is for how long? The tests above were done shortly (days) after treatment. Does the flexibility last multiple years, or does the effect wear off too quickly for it to be significant? There isn’t a published long-term study tracking flexibility over time post-treatment. The companies typically claim about five years of improved performance, but further independent verification of that timespan is not available.

Granule Adhesion and UV Protection

Another common claim is that rejuvenation will stop the excessive loss of granules (the colored mineral grit on shingles). Granules are critical because they protect the asphalt from UV rays and provide fire resistance. Granule loss is a normal aging symptom – you’ll often see granules start to collect in gutters as roofs get older. Fewer granules means less UV protection and faster asphalt degradation. The rejuvenation idea is that by replenishing oils, the asphalt becomes sticky/binding again and holds the granules better.

Standard test ASTM D4977 (also referenced in ASTM D3462) uses a brushing machine: a steel brush scrubs a shingle sample for 50 cycles and the dislodged granules are weighed​. New shingles typically lose ≤1.0 gram of granules in this test. What about old vs. treated?

• OSU/Roof Maxx results: The treated shingles showed a dramatic improvement. According to the report, granule loss in the brush test decreased by 46% after treatment compared to the untreated shingles​. In fact, the treated 17-year-old shingles had granule loss levels “close to those of new shingles.”​ They report an average granule loss of about 0.55 g for treated vs 1.02 g for untreated in one set of tests (the full data isn’t in the study summary I’m using, but a 46% reduction is noted)​. This implies that the rejuvenator re-bonded some loosening granules or at least made the asphalt less likely to shed more. The result is statistically significant. The authors of the OSU study were impressed, stating it “restored the old shingles to properties close to those of new shingles” in terms of granule adhesion​.
• Greener Shingles/PRI results: Even more striking – but note, they tested on organic-mat shingles (which haven’t been produced by a major manufacturer since 2012) which tend to lose granules badly when aged. The untreated samples lost on average 1.12 g of granules in the test (which is actually a failure by new shingle standards, >1.0). After treatment, the loss was only 0.15 g. That’s an 86% improvement – bringing a failing shingle well within the passing range. They did both dry and wet scrub tests; both showed the treated shingle outperforming the old one by a large margin. This suggests the bio-oil treatment significantly increased the asphalt’s bond with the granules. The discussion in that report even notes this as a major benefit of the treatment.

Real-world, this could mean fewer granules washing off after each rainstorm and a roof retaining its protective mineral surface longer. And once again, the question of how long this effect lasts is still a concern.

One caveat: If a roof has already lost a lot of granules (bare spots), a spray can’t put them back. It might help retain those that are loosening but still present. Some treatment applicators add loose granules by hand to bald spots in conjunction with spraying – but that’s a very patchwork fix. Homeowners shouldn’t expect a roof with thin granules or a bald roof to magically grow a new coat of granules from a treatment. The best candidates are roofs that still have most of their granules intact so the oil can preserve what’s there.

Water Permeability and Weatherproofing

An interesting test performed by OSU was water vapor transmission (ASTM E96) to address concern that the treatment might be creating a vapor barrier, which is one of the main issues that ARMA has with traditional roof coatings being applied to shingle roofs. The question: does treating make the shingles so “sealed” that they trap moisture inside the roof system? We have data comparing permeability of old untreated vs. old treated shingles.

• The OSU report found that Roof Maxx reduced the water vapor permeability of the aged shingles by about 60%, bringing it closer to that of fresh shingles​. In technical terms, an untreated 17-year shingle had around 10 perms of vapor transmission, whereas after treatment it was around 3 – 4 perms. For context, a brand-new shingle is very impermeable (on the order of 0.5 – 1 perm)​. So even after treatment, the old shingle was still more permeable than a new one – but much less than it was untreated. Essentially, the oil filled some micro-gaps and pores, slowing moisture diffusion through the shingle. OSU’s phrasing: “Roof Maxx improved the permeability by about 60%, restoring values closer to those of new shingles.” They emphasized that it did not fully equal a new shingle, but did move in that direction.

Practically speaking, this means a treated roof is less likely to absorb moisture (either ambient humidity or wind-driven rain) through the shingle layers, which is a good thing for waterproofing. Yet it’s still “breathable” to a degree – avoiding the trapped moisture that ARMA is worried about. The treated shingles were around 3 perms; in building science, anything above 1 perm is considered permeable. So, while the shingles become more water-resistant, they aren’t turned into a vapor-sealing layer by the oil spray.

It’s also worth noting that these rejuvenator products dry clear and don’t form a continuous film like a paint or typical roof coating would. So pathways for vapor (like laps and gaps between shingles) remain. The reduction in permeability is likely due to plugging microscopic cracks in the asphalt coating of the shingle itself, rather than creating a new waterproof layer over the entire roof.

Small Leaks and Waterproofing: Can these treatments stop leaks? If the leak is due to shingle porosity or hairline cracks, theoretically, yes – saturating the shingle could seal those tiny openings. But most roof leaks occur at flashings, valleys, vents, or from larger failures (blown off shingles, big cracks)​, so probably not. A spray won’t fix a failed flashing or a missing shingle. Rejuvenation is preventative more than curative.

Some homeowners have reported that after treatment their occasional small leak in a certain spot stopped – but such evidence is anecdotal. Contractors emphasize that you cannot rely on a treatment to solve an active leak in lieu of proper repair. In fact, ARMA’s bulletin explicitly cautions that assumed leak remediation benefits of coatings (which are far more waterproof than rejuvenation treatments) are unproven​. So, while it might slightly improve the general water-shedding capacity of the shingles, you should repair known issues first.

Any reputable roof rejuvenation dealer will insist on replacing any damaged shingles and repairing any failed flashing before applying the treatment.

Hail Impact Resistance

Hail can wreck an asphalt shingle roof by knocking granules off and cracking shingles. Some rejuvenation companies suggest a treated roof is more resilient – that it could even achieve a Class 4 impact resistance rating (the highest, normally associated with specialty impact-resistant shingles).

The data here is limited:

• PRI tested treated vs untreated shingles with a 2-inch steel ball drop (UL 2218 Class 4 simulation). On the organic shingles in the Greener Shingles test, they saw only a 6.6% improvement in impact performance after treatment. The measurements (dent sizes or damage areas) were slightly smaller in treated shingles, but not by a wide margin: average indentation maybe 0.113 inches deep treated vs 0.121 inches untreated. They noted the improvement was minimized by the shingle type (organic felt shingles tend to absorb impact differently than fiberglass ones) and speculated that fiberglass shingles might see a larger benefit.
• The OSU/PRI report qualitatively said that in the Class 4 hail test on a test deck, both treated and untreated showed “visible depressions” after drops, but presumably neither cracked through (passing Class 4 means no crack on the backside of the shingle). Unfortunately, the OSU summary didn’t explicitly state “pass” or “fail,” just that depressions were seen. It’s likely the untreated 17-year-old shingles might have failed a Class 4 test (old brittle shingles often do crack under a 2” steel ball impact), whereas the treated ones possibly passed (no crack). If they did, that’s a meaningful outcome – it could mean an old roof might survive moderate hail where it wouldn’t have before. But one controlled test is also no guarantee that the shingles would perform well in a real hailstorm with countless hits and cold temperatures.

Contractor observations put this in perspective. This Able Roofing blog post stated that “A diminished impact depression was noted on the treated shingles, but only slightly less than untreated. The treated and untreated shingles were still damaged to the extent that insurance would cover a full roof replacement.”​

In other words, in a hail scenario big enough to normally justify an insurance claim, the treated roof didn’t do so well – maybe the dents were a bit shallower, but not enough that it wasn’t still serious damage. In fact, this contractor warns that if the treatment makes the damage slightly less obvious, an insurance adjuster might try to deny the claim. This is an unintended consequence: a partially “strengthened” old roof might survive marginal hail, but if it’s truly large hail, you’ll still need a new roof and now you might have to argue about how damaged it is. This is speculative, but a point to consider – rejuvenation is not equivalent to installing higher impact-rated shingles.

Fire Resistance

ARMA raised a red flag that adding oils could make flames spread easier on a roof (oil is flammable, after all). The rejuvenation companies responded by doing fire tests.

• PRI conducted a spread-of-flame test (a proprietary test analogous to ASTM E108, the standard for roof fire ratings) on treated vs. untreated shingles. The result: “no visual difference between the spread of flame” for the untreated and Roof Maxx treated shingles. In other words, the flame spread across the roof sample was similar in both cases, suggesting the treatment did not make the roof more flammable. The OSU report concluded Roof Maxx “does not increase fire risk.” They reference that a Class A fire rating was maintained in their evaluation​.
• Interestingly, the Greener Shingles test even showed less flame spread on treated shingles: 86 in² area vs 144 in² on untreated. That was unexpected – possibly the oil had some flame retardant effect or the extra mass in the shingle delayed ignition. In any case, it certainly did not worsen the fire performance in that test. The PRI report noted this “distinct benefit” and recommended further investigation on why the flame spread was reduced.

So the fear of turning your roof into a torch by spraying plant oil on it seems unfounded, at least for the products tested. It does make sense – these oils have high flash points and are applied in fairly small quantities. Also, once absorbed, they’re within the shingle matrix. Roofing asphalt itself is derived from petroleum and shingles have to be formulated to meet fire ratings even though asphalt can burn; additives to the asphalt, the granules, and the fiberglass mat all provide fire resistance. A small amount of soybean oil would likely burn off quickly or maybe it can’t sustain a flame by itself.

That said, formal fire rating of the entire roof system would require a certified test (ASTM E108 on a full assembly). To my knowledge, no rejuvenation product has gone through the full certification to say a Class A fiberglass-asphalt shingle roof remains Class A after treatment. The preliminary tests indicate it should, but local code officials might not recognize that without a specific official standard rating. So, while fire risk to your home doesn’t seem to actually increase, there is a gray area regarding the code classification. Homeowners in jurisdictions that require Class A roofs (wildfire-prone areas) should be cautious – technically, any modification may void the original roof certification. You would probably want to get something in writing from the product manufacturer about fire tests if this is a concern.

Roof Service Life Extension

So last but not least, here’s the million-dollar question: Does a treatment actually prolong the useful life of the roof, and by how much? This is very hard to answer because it can only be proven over time, in real world conditions. These products have not been around long enough for a significant body of reliable data to develop, so we can only guess based on warranties, limited field studies, and personal anecdotes. As to whether these products actually significantly extend the service life of a roof (and by that I mean do they do enough good to be worth the money), I get the feeling that it’s too soon to know for sure.

Ideally, we would have tests performed on actual roofs where, at about 15 years old, one half of the roof gets treated and the other half isn’t, and then the roof could be monitored for the next 20 years to see what effect the treatment (and subsequent periodic treatments) had. We don’t have anything like that, so we have to try and make the best guess we can.

• Current Evidence: What we know is largely based on manufacturer-sponsored testing and accelerated aging simulations, not decades of actual field data. As of now, these rejuvenation products have only been around for a few years (many were launched around 2017-2019), so there is a limited number of real roofs that have been observed 5+ years after treatment to confirm these longevity claims.
• Manufacturer Warranties: Most rejuvenation companies themselves are conservative here. They typically offer a very limited 5-year warranty that the shingles will remain flexible and if they don’t, the company will retreat the affected area​. That’s it. Remain flexible and retreatment. Roof Maxx gives a 5-year transferable warranty after each treatment. This does imply that they expect the benefits to last at least 5 years before needing reapplication. They do not claim that the effects of one treatment last 15 years. To get the “up to 15-years” worth of benefits, they propose retreating the roof every 5 years for continued protection. So the “up to 15 years” period that is often quoted is based on doing it multiple times.
• Ohio State University’s assessment: The OSU researchers cautiously concluded the product “exhibits great potential to be an economical biobased solution for maintaining and increasing a roof’s service life.” They didn’t put a number on it, but the tone suggests a expectation that it can indeed extend roof life, given the lab performance. They also noted the benefit of reducing waste (every year of roof life extension is a reduction in landfill waste).
• Anecdotal field cases: These products have been widely marketed to homeowners since around 2017-2018 and there are now thousands of treated roofs. We have some homeowner testimonials like: “my 20-year-old shingles were curling and dry, and after treatment they lay flatter and looked darker, and 3 years later they’re still in good shape.” There are also the negative anecdotes (we’ll cover this in the Criticisms section below) where someone treated a roof and it still failed soon after. It largely depends on the condition of the roof at the time of application. A common warning from contractors: “If a roof is at the end of its lifespan or has major issues, a treatment won’t save it.” But if a roof is aging normally and you treat it at, say, 15 years, it might reliably get you to 20 or 25 years. (Then again, this could happen without the treatment.) Many dealers have done retreatments on the same roof after 5 years, indicating that those roofs did last at least that long and presumably benefited enough that the owner decided to do it again.

The claims of increased lifespan appear to have some backing in scientific tests (improved flexibility and durability metrics) and field reports (roofs that seem to be holding up longer than they might have without treatment), but we should be very cautious about assuming any set maximum values. A safe conclusion: a rejuvenation treatment might get a few more years of service out of an aging roof, delaying the need for replacement – but results will vary. The widely advertised “15 extra years” is likely an upper-bound scenario for a roof that was treated multiple times under ideal conditions and would have lasted several years longer anyway.

Known Limitations and Factors Affecting Results

Not every roof is a good candidate for rejuvenation, and even for the ones that are, certain factors can influence how effective the treatment is and how long it lasts:

• Extent of Existing Damage: Rejuvenators are supposed to work on aging, not damage. If a roof has widespread cracks, holes, delamination, or missing shingles, an oil spray won’t magically fix those. Manufacturers typically require the roof to be in generally sound condition (no active leaks, no major sections missing). One rule of thumb mentioned by an industry observer: at least 60% of the granules should still be intact on the shingles for rejuvenation to have something to “rejuvenate”. If the roof has large bald patches or the asphalt is already severely deteriorated, there’s little base material left to save. In such cases, a reputable rejuvenation contractor might actually decline to treat the roof and instead recommend replacement. A less scrupulous vendor might spray it anyway. Rejuvenation is only suitable for roofs that are aging but not beyond hope. Think of it as for a roof that’s in the last third of its expected life, not one that’s already a candidate for replacement.
• Climate and Weather Exposure: Climate can play a role in how well the treatment holds up. Very hot climates with intense UV might cause the added oil to degrade faster (more UV means quicker oxidation of both asphalt and the bio-oil). Very wet climates could potentially wash out some of the oils sooner, or high-elevation zones with intense UV and big temperature swings might stress the shingles more than average. Very cold climates with heavy freeze-thaw cycles might also limit the effectiveness of the treatment. If moisture does get into the shingles and freeze, no oil will stop that expansion damage. However, the reduced permeability could mean less moisture enters to freeze in the first place, which would be a plus. That said, the base issue – the asphalt drying out – happens in any climate, just at different rates. No published study yet has broken down performance by climate region, so we’re left to extrapolate. The application itself is weather-sensitive: you generally need a certain temperature (often >50°F) and dry conditions for at least 24-48 hours for the treatment to be applied and absorbed properly. You wouldn’t apply it in the middle of winter or during rainy season. This means in cold climates, rejuvenation may be a spring/summer/fall project only. Once applied and cured, rain won’t wash it off (it soaks in and dries to an extent), but if heavy rain hits too soon right after application, it could dilute or wash off the product.
• Age of Roof at Treatment Time: All providers stress that roofs need to be in repairable condition – typically meaning less than 20 years old for standard shingles, no active leaks, no more than 10-20% of shingles damaged. In theory, there’s an optimal window for rejuvenation. If done too early (say on a 5-year-old roof), it’s unnecessary – the shingles haven’t lost enough oils yet to justify it, and you might even negatively interfere with the roof’s own aging process or the manufacturer’s warranty. If done too late (like 25-year-old 3-tab shingles that are starting to crumble), it’s like giving vitamins to a corpse. (Roof Maxx says they’ve done roofs up to 30 years old, but that’s probably exceptional and most roofs that old would be unsuitable.) The best candidates are roofs that are just starting to show signs of drying out: perhaps 14-17 year-old architectural shingles or 7-10 year-old 3-tab shingles in a hot climate (3-tab have shorter lifespans). At that stage, you might see some granules in the gutter, maybe the color is starting to fade or the shingles feel less pliable, but they aren’t leaking or breaking apart yet. The Roof Maxx Ohio State study tested 17-year-old shingles, which is right around when many shingles become embrittled. Timing is also tied to the warranty: most rejuvenation companies try to target roofs that are just out of or near the end of their original material warranty.
• Preparation and Application Quality: The effectiveness of the treatment can be heavily dependent on the application process. The roof should be cleaned first, often blown off or gently washed to remove dirt, moss, and other debris so the product can fully come into contact with the shingles. If a company pressure washes the roof aggressively, they will likely do more damage (by blasting off the granules) than the treatment can compensate for. ARMA explicitly cautions against pressure washing shingles due to the risk of damage​, so a competent rejuvenation service will avoid high-pressure cleaning. Some use a “soft wash” (low pressure with a cleaning solution, often a bleach mixture to kill algae). If not done properly, even that could potentially affect the shingles (for instance, bleach can negatively react with asphalt if not rinsed off). After cleaning, the spray must be evenly applied in the correct amount. Too little, and you don’t achieve the desired saturation; too much, and you could over-saturate and cause a mess or even excessive shingle softening that takes a long time to resolve. The applicators should also cover or protect surrounding landscaping, windows, etc., from overspray. A skilled, trained applicator is important – if someone just buys some rejuvenator and DIY sprays or a non-roofer handyman tries it without having a thorough knowledge of roofing, results could vary. A sloppy job could lead to inconsistent treatment or other collateral issues.
• Multiple Treatment Limitations: If one treatment adds ~5 years, can you keep doing it forever? No. There are diminishing returns and practical limits. Most companies cap at 3 treatments (approximately +15 years). By that time, the roof would be very old, well beyond its design life. Even with added oils, the shingle mat and other roof components can deteriorate (the fiberglass mat could delaminate, etc.).
• Maintenance after Treatment: Does the homeowner continue to maintain the roof (keep it clean of moss/debris, fix minor damage)? A rejuvenation isn’t a free pass to neglect the roof. Roof material warranties typically will be void if you don’t repair storm damage. A treated roof still requires normal care. If you have the roof treated and then never clean the gutters or never inspect it, it could still develop issues that shorten its life.

Criticisms & Skepticism

Despite the promising idea of roof rejuvenation, there is significant skepticism in the roofing community. Many veteran roofers and roofing industry experts remain unconvinced that these spray-on treatments can provide provable long-term benefits for an aging roof. It’s important to take that into account. Roofing contractors can draw on their own actual experience with a statistically significant number of real roofs to form their conclusions. Homeowners can’t, so they generally have to put their faith in either the roof treatment marketers or the members of the roofing community who don’t believe the treatments do much good. This is a difficult position to be in. Here are the main points of criticism and some real-world cautionary tales:

1. Temporary Fix, Not a Real Solution: A common criticism from roofers is that while rejuvenation may let you put off a roof replacement for a little while, it isn’t worth the price. It might help marginally and temporarily, but it doesn’t actually roll back the clock on a failing roof. As one roofing company put it, “Financially it makes more sense to forego the roof sealant and invest in a roof replacement… If your roof is failing or showing its age, stop putting off the inevitable. Investing in a temporary fix will only end up costing you more in the long run.”​.

Of course, this view can be seen as self-serving (roofers make money by replacing roofs), but it does have some logic behind it: if you spend, say, $3,000 on a treatment and get 3-5 more years, and then still pay $15,000 for a new roof, your total outlay becomes $18,000 for maybe 3-5+X years of roof. Could it have been cheaper in the long run to just replace it earlier? Possibly, especially if the roof was going to last 3 years anyway without treatment. And there’s no real way to know that for sure.

Another big concern is that homeowners might use a rejuvenation treatment on a roof that really should be replaced, and then suffer a failure or leak that causes serious interior damage – costing more than if they had replaced the roof proactively. “Don’t gamble with a failing roof” is the advice; use rejuvenation only if the roof is still in decent shape. But then why use it at all?

2. Doesn’t Address Underlying Issues: Shingle rejuvenator sprays only affect the shingle surface. They do not fix issues with the roof’s structure, decking, flashing, or ventilation. Most roof leaks occur at flashings (around chimneys, skylights, valleys) or roof edges, and rejuvenation does nothing for a piece of loose flashing or a cracked pipe boot​.

If nails have backed out or if there’s poor attic ventilation causing condensation or overheating the shingles, those problems will persist. Some older roofs may have brittle underlayment or rotten wood decking under the shingles; a surface spray is irrelevant to those hidden issues. So critics say it gives a false sense of security if homeowners think their roof is “good as new” after a treatment. The top reasons roofs leak (failing flashing, fastener issues, punctures, etc.) are not cured by rejuvenating shingles.​

In fact, rejuvenation companies usually will refuse to treat a roof with known leaks or damage until those are repaired. This underscores that it’s not a fix for everything.

3. Limited Long-Term Proof: As I’ve mentioned over and over, these products haven’t been used widely enough or for a long enough amount of time for any real-world evaluation that I find credible. The data is too sparse. I (and many others) want to see independent field studies showing that a treated roof conclusively lasted X years longer than an untreated roof of the same age, with the same materials, in the same location. And I want to see a study that includes enough roofs to be statistically significant. Right now, the evidence is limited to a couple of lab tests and anecdotal short-term observations.

From a skeptic’s standpoint: the tests show immediate improvements in desirable asphalt properties, but do we know the effect after 5, 7, 10 years of weathering? Not yet, at least not from any reports I could find. Until a statistically significant number of roof replacements can be shown to have been delayed, with a worthwhile cost savings, and it can be proved that it was due to these treatments, many experts will remain unconvinced.

4. Potential for New Problems: While test data so far is reassuring, roofers think about worst-case scenarios:

• Surface slipperiness: Right after application, the roof can be slick (oily). Workers or homeowners going on the roof could slip. Even after drying, an oily residue might attract dust or foster mildew (this hasn’t been reported, it’s a theoretical issue).
• Interaction with Shingle Sealant: Asphalt shingles have a factory-applied adhesive strip that bonds each shingle to the one below for wind resistance. Will the rejuvenator soften or dissolve these seals? Could that cause sealed shingles to unstick? In the short term, during application, possibly yes – the oils could temporarily weaken the bond until they evaporate/absorb. The OSU test noted improvement in flexibility “weather-side down” (simulating wind lift)​, which suggests the shingle was able to bend upwards without cracking and presumably without tearing away from the course below – perhaps because the seal either held or the shingle was flexible enough even if partially unsealed. There’s some unknown here. The PRI report discussion explicitly raises the need to examine impacts on “Wind Uplift… and Tab Sealant Adhesion.” They did not find a problem in initial tests, but it’s flagged as a concern. Roofing contractors fear a scenario where shingles could peel up in a storm if the adhesive bond is compromised. On the flip side, some suggest the oils may actually rejuvenate the adhesive strip as well and help the shingles bond better once it sets. There isn’t clear evidence either way yet.
• Aesthetic issues: If a rejuvenation spray is over-applied or applied unevenly, you might get a blotchy appearance. Most products dry clear/dark and make the roof look more uniform (many homeowners say their roof looked “like it was new again” color-wise because the faded roof darkened), but a poor job could leave irregular coloring. Additionally, it will not fix algae stains or lichen – those need to be cleaned off first. One roofer noted “adding a roof treatment will just coat the stain and lock it in”​ – so if your roof had black algae streaks, and the contractor didn’t remove them, a clear rejuvenator might simply seal those streaks in place (they might fade a bit from the oil, but not disappear). The treatment also won’t uncurl bent shingles (they may soften slightly but not enough to flatten badly deformed shingles).
• Over-spray and environmental concerns: While marketed as safe, there’s a practical matter of overspray. The mist can get on siding, windows, plants. Typically it’s rinsed off and doesn’t stain (since it’s mostly water and soybean oil), but if not done carefully it could make a mess. Imagine an oily film on your windows or car. Skilled applicators can usually avoid this, but getting a careless applicator is possible. Also, oil running off in rain might leave slight residue around the house initially (though they’re biodegradable and not known to cause plant harm).
• Fire classification: As discussed, even if the fire performance is fine, the roof is technically “altered.” A home inspector or fire marshal could raise an eyebrow if they know a roof was coated with something, because it deviates from the listed assembly. Most likely this is a non-issue in practice (and as tests show, there’s no increased flammability), but an inspector could make it an issue if he wanted to.

5. Questionable Marketing Tactics: A lot of skepticism comes from how these products are sold. Many rejuvenation companies operate on a franchise model where local dealers buy into the brand and are taught to sell the service. Inexperienced or aggressive dealers might over-promise results. Roofers have reported seeing door-to-door salespeople pushing roof treatments in neighborhoods, which raises a red flag due to the high-pressure tactics.

Homeowners should be wary of any unsolicited “your roof needs this treatment or it will fail” scare approach. Some detractors call it “snake oil” implying that it’s just clever marketing playing on homeowner fears of roof failure while delivering minimal real benefit. The term “snake oil” is harsh (as we’ve seen, there is some real science to support the concept). But if sold inappropriately, it could certainly feel like a scam to a burned customer.

6. Mixed Consumer Experiences: While many homeowners report satisfaction with rejuvenation treatments, mentioning the improved appearance and performance of their roofs, there have also been some documented negative experiences, particularly around mismatched expectations:

• Complaint from July 2024 (BBB): One homeowner noted frustration after a roof rejuvenation service, stating, “Paid them… Service performed… Absolutely no change to roof.” In this case, the applicator reportedly left mid-job due to rain and did not return to complete the service, leaving the homeowner dissatisfied and questioning the treatment’s effectiveness. This highlights a critical issue: if customer expectations are not properly managed, homeowners may feel misled or disappointed when immediate or dramatic changes are not visible. Improvements from rejuvenation treatments can often be subtle rather than transformative, particularly if the roof is already severely deteriorated.
• Complaint from 2023 (BBB): Another homeowner expressed disappointment after investing $2,950 in a Roof Maxx treatment, only to find that their roof still required replacement soon afterward. The homeowner stated, “Now we still need to replace the roof.” The frustration stemmed from feeling misled about the extent to which the treatment could prolong the roof’s life. In this instance, the complaint was resolved, apparently through a refund or application of costs toward replacement. But this underscores the risk: rejuvenation treatments can feel like wasted money if the roof’s underlying condition or subsequent weather events negate any benefits.

These experiences emphasize the importance of clear communication regarding realistic outcomes and limitations of rejuvenation treatments. Homeowners should carefully assess their roof’s current condition and set practical expectations with providers before proceeding.

7. Professional Backlash: Some roofing contractors naturally disparage these treatments because it cuts into their roof replacement business. You may take their disapproval with a grain of salt for that reason. But even objective experts with nothing to gain either way (me, for example) express concerns that the concept sounds too good to be true and want to see more evidence. It often takes decades for new roofing techniques or products to gain acceptance. Roof rejuvenation is a new entry in an old-fashioned industry, so pushback is natural. Experts also caution that some new companies may lack proper roofing expertise. A franchisee could just be a salesman with a ladder, not an experienced roofer. If they miss something (like deteriorated deck areas or improper flashing) and just spray, they could create a false sense of security.

Critics urge homeowners to not be swayed by marketing alone and to critically assess their roof’s condition. If your roof is in reasonably good shape and just aging, a rejuvenator might help, but if it is substantially deteriorated or has real damage, you’re better off putting money into proper repairs or replacement.

Next, we’ll consider the costs, potential risks, and trade-offs in detail, to see when (if ever) rejuvenation treatments make sense financially.

Costs, Risks & Potential Trade-Offs

The main selling point of shingle rejuvenation is cost savings, but homeowners need to weigh the true costs (including repeat applications) against the benefits, and should consider any risks involved. Let’s break down the cost aspect, then list the risks and trade-offs.

Comparative Costs: Rejuvenation vs Repair vs Replacement

A full asphalt shingle roof replacement is expensive: often $8,000 to $20,000+ depending on roof size, materials, and local labor rates, averaging around $5 to $8 per square foot. Rejuvenation is marketed as a bargain by comparison. Typical costs reported:

• Rejuvenation Treatment: Roughly 15% – 25% of the cost of replacement for a one-time treatment​. So if a new roof would cost $15,000, a treatment might cost around $2,250 – $3,750. A common estimate is around 20% of replacement cost​. Roof Maxx dealers often charge about $0.80 to $1.25 per square foot. For a 2,000 sq. ft. roof (20 squares), that’s $1,600 – $2,500. Roof Magazine notes that a 2,500 sq. ft roof costs $3,000 – $6,000 for Roof Maxx​, which aligns with that range (perhaps higher in some regions or if extra services like cleaning are included).
• Repairs: If your roof just has a few non-systemic issues (like a couple of leaks or some damaged shingles), repairs might cost less than a thousand dollars. For example, replacing your chimney flashing or a few shingles here and there might cost $500. And a rejuvenation treatment is not a substitute for repairs. You might actually need to get those repairs done and pay for the treatment on top of that. For isolated problems, it’s often more cost-effective to repair the roof rather than treating it.
• Roof Replacement: A full asphalt shingle roof replacement is typically a significant investment, ranging from $8,000 to over $20,000 depending on roof size, shingle product line, roof complexity, and regional labor rates. The average price generally falls between $5 and $8 per square foot. While costly, a complete replacement provides a completely fresh start, gets rid of your existing roof issues along with the old roof, and is typically backed by a manufacturer warranty and a 5- to 20-year workmanship guarrantee, ensuring long-term protection and peace of mind.
• Coatings (Reflective or Sealant Coatings): These are not typically intended for shingle roofs (and not recommended by ARMA), but for comparison, a high-quality silicone or acrylic roof coating might cost $1-$2 per square foot, similar to rejuvenation treatments. But those coatings often come with 5-10 year product warranties and can extend roof lifespan if done right. They also might require multiple coats. The cost difference between a rejuvenator and a full elastomeric coating may not be huge, but coatings carry their own downsides (weight, appearance, warranty voidance, etc.).

Value: If a $2,500 treatment really gives you five more years on a $15,000 roof, that’s $12,500 that you can put off spending for those five years. If you then treat again (another $2,500) for another 5 years, you’ve spent $5,000 total to postpone a $15,000 job by 10 years. That’s $10k you’ve kept in your pocket (not factoring inflation, in 10 years a new roof might cost $20k, so you saved even more in future dollars). This is the ideal scenario pitched by roof treatment companies.

But what happens if the roof only lasts, say, 3 extra years and then you have to replace it. You spent $2,500 to delay a $15k cost slightly, and maybe during those 3 years you still had to pay for a couple repairs. The ROI in that case is poor. You might have been better off replacing the roof and getting 20-30 years out of the new roof.

And what if the roof would have lasted the extra time without the treatment? And how would you know?

The cost-effectiveness largely depends on:

• How much longer your roof actually lasts with the treatment vs. without it. Test results or other data that allow you to accurately predict a value for this do not seem to exist.
• Whether you need to re-treat (incurring repeated cost).
• Whether avoiding replacement now is a priority. Maybe you plan to move in 3 years, so you don’t want to spend $15k on a new roof you won’t benefit from. A $3k treatment to keep it leak-free until you sell the house might be something you want to do.
• Inflation and rising roof prices: delaying replacement could mean you pay more later as roof costs go up. You have to weigh that against the time value of your money (not paying today means you can invest that money elsewhere).
• If your roof is in a marginal state such that an insurance claim might be possible due to storm damage, treating it might make it resilient enough that you’ll miss out on a getting a new roof paid for by insurance (one could cynically view that as a lost opportunity for a “free” roof, though of course no one wants damage to their home).

Costs in Context: Many rejuvenation treatment dealers will also include ancillary services in their price: gutter cleaning, minor repairs (caulking exposed nail heads, replacing a handful of bad shingles), soft washing the roof for moss/algae removal, etc. These have value too. If included, then the price is a bit more justified as comprehensive maintenance.

Risks and Trade-Offs

I mentioned risks earlier, but let’s list them clearly:

• Fire Rating Uncertainty: While tests show no increased flame spread​, applying any aftermarket product technically voids the UL Class A fire rating unless that product is tested and listed as part of a system. The trade-off is between a very low probability issue (fire performance change) versus the benefit of extended life. Most would accept this risk, given data so far, but you should be aware of it. In high fire-risk areas, replacing a roof with Class A materials might be preferred over treating an old roof that may not perform to a Class A level in extreme fire conditions (though likely it would, given the test results).
• Warranty Voidance: If your roof is still under a manufacturer’s warranty, using a rejuvenator may void it (unless the manufacturer explicitly allows it, which doesn’t seem to happen). For example, if you have a 50-year shingle that’s only 10 years old (and especially if you have a extended warranty), think twice. However, Roof Maxx says that they haven’t seen any warranty denials yet due to their product​, and they also offer their own warranty.
• Voiding Insurance for Old Roof: Actually, in some cases it’s the opposite: not improving roof performance could void insurance if they decide your roof is too old. Some insurance policies won’t cover damage on roofs over a certain age unless they are certified as still in good condition. A rejuvenation treatment could serve as evidence that the roof was maintained. Most sources say insurance is not voided by these treatments​. So insurance risk is low; the bigger risk is relying on an old roof beyond its intended life (with or without treatment) and then having a claim denied because of roof age. The treatment might or might not help you in that scenario.
• Environmental and Health Risks: These products are generally safe. Soy oil is even food-grade in some cases. Runoff won’t poison your lawn. There’s no significant chemical fume or odor after application; during application, mild odor or overspray mist is possible. Compared to many home improvement chemicals, these are benign and environmental risk is low. There is a small risk of slipping if you walk on the roof or even the ground right after. The oil overspray on a ladder or deck could cause slips, so the application crew and homeowner must be cautious until everything is dry.
• Shingle Appearance and Color: As mentioned, one effect is the shingles often darken to a color closer to the original. Many people consider this a plus because the roof looks newer. But if someone had a weathered roof that looked good, that will change. Also, the color change tends to be temporary; the roof will gradually fade again as the oil slowly becomes depleted. Farm Progress noted the solution “goes on white and dries clear, restoring the natural color of the shingles”​. So expect a visual change (usually uniform darkening). Check for any staining on other materials.
• Repeated Applications: Diminishing Returns? If you plan to have your roof successively re-treated in order to put off roof replacement as long as possible, it’s important to evaluate costs and long-term effectiveness. Treatment manufacturers typically suggest re-treating every 5 years to replenish the oil, which naturally weathers away over time. But there is a practical limit. Most rejuvenation treatment companies, including Roof Maxx, recommend no more than three applications, which theoretically could extend a roof’s life by approximately 15 years in total. The maltenes aren’t the only part of a shingle that degrades over time, and other roofing system issues will typically emerge. Repeated treatments can’t indefinitely postpone roof replacement. Homeowners should also consider long-term product and company availability. There’s a risk the rejuvenation product, formula, or company itself may no longer exist when future treatments are needed.
• If It Fails to Deliver: The worst-case scenario is you pay for the treatment and the roof still needs to be replaced soon after (like the BBB complainant). That money will have been wasted. Some dealers might offer to credit the cost toward a new roof (if they also do roof replacements). It might be worth negotiating such an arrangement (though many rejuvenation treatment franchises do not do replacements – they stick to their niche, so that may not be an option).
• Interaction with Future Roofing Work: If you treat the roof now and then decide to replace the roof two years later, will the treated shingles be harder for a roofer to deal with (sticky and harder to tear off)? Probably not; it shouldn’t affect tear-off or the installation of new shingles.

Advice for Homeowners

If you’re a homeowner considering an asphalt shingle rejuvenation treatment, you need to approach it with informed caution. Here are key “red flags” to watch for, critical questions to ask providers, and some cost-effectiveness insights for the budget-conscious homeowner.

Red Flags When Evaluating a Roof Rejuvenation Service

• High-Pressure or Alarmist Sales Tactics: Be wary of someone who knocks on your door and insists your roof must be treated immediately to avoid disaster. Scare tactics like “your roof will fail if you don’t do this now” or limited-time offers are classic signs of a scam. Reputable companies will inspect your roof and give an honest assessment, possibly even telling you that you don’t need their service if the roof is still in great shape or conversely that your roof is too far gone for their service. If you feel rushed or frightened into a decision, they are probably trying to scam you.
• No Detailed Roof Inspection: If a contractor is willing to spray your roof without even getting up on it to check its condition, that’s a red flag. A proper dealer will inspect the roof, measure the roof, and identify any repairs or cleaning needed beforehand. If they don’t mention doing minor fixes or cleaning before treatment, they are probably not someone you want to do business with.
• Promises to Fix Active Leaks or Major Issues: Remember, roof rejuvenation treatments are not a fix for existing leaks or significant damage. If a salesperson claims “this will solve your leaks” without addressing the actual leak source, be skeptical. The correct approach is to properly fix any leaks first. Anyone suggesting skipping the necessary repairs is misrepresenting the product’s capabilities.
• Lack of References or Local Portfolio: Ask for addresses of homes they’ve treated in your area or references you can call. If they can’t provide any, and if they don’t have a local physical office, you might be dealing with a fly-by-night fraudster. Established dealers will have a track record.
• Not Mentioning Manufacturer/Industry Stance: A trustworthy contractor should be upfront that roofing manufacturers don’t officially approve these treatments. They might explain the testing that’s been done and why they believe it’s effective despite ARMA’s general disapproval. If they seem unaware of or dismissive about questions concerning roofing warranties, that indicates they might not really know much about roofing.
• Unwillingness to Provide Documentation: You have the right to ask for copies of the product’s technical data sheet, MSDS (material safety data), the warranty terms, and any test results or case studies. If they resist providing you with this information, it’s a bad sign. Transparent companies will have a brochure with FAQs and reputable sources for their claims.
• Overstating the Benefits: If someone says “this one treatment will make your roof last 15 more years guaranteed,” that’s an overstatement. The guarantee is likely 5 years, not 15, and “up to 15” involves re-treatment. Watch for misrepresentation. Legit dealers will clarify the 5-year interval plan. Also, if they claim it makes the roof as good as new in every aspect, that’s hyperbole. It can make old shingles behave more like newer ones in some ways, but your roof will still be old and subject to other avenues of failure.
• Extremely Low Price or DIY Offer: If you encounter a price that’s dramatically lower than others or someone selling a do-it-yourself version, be cautious. These products require proper application (correct coverage and application technique) to work. Too low a price might mean they skimp on coverage or are using a knock-off product. Also, DIY application by an untrained person could lead to uneven results or safety issues. Stick with authorized dealers from known companies.

Questions Homeowners Should Ask

When getting an estimate or considering a service, ask the following:

1. Is my roof a good candidate for this treatment? Invite an honest assessment. If the rep doesn’t set any conditions (like “you need to have at least 75% of granules intact, no more than minor leaks, etc.”), they probably do not represent a reputable company. A good answer would detail the roof’s condition and why it can benefit or not.
2. What exactly is the product being applied? Have them describe the formulation (“100% natural plant-based oil, NSF food-grade safe” or something like that) and provide proper product safety documentation. You want to know it’s not something like used motor oil (there have been horror stories of scammers spraying waste oil on roofs, which would darken it but actually damage the shingles). The mainstream products are all rigorously tested, so confirming the brand name and details is important.
3. Do you do any cleaning or prep beforehand? Most roofs should be clear of debris and moss before treatment. Some companies include a gentle wash or air blowing. If your roof has algae, ask if they will address that (some treatments might kill algae due to the oil, but typically you’d want the dead algae cleaned off). If they plan to apply over a dirty, mossy roof, that’s a very bad sign.
4. Will you perform any minor repairs as part of the service? Often, replacing a broken shingle or re-caulking a vent is needed. Some dealers do this inclusively or for an extra charge. Knowing this upfront ensures you’re not left with untreated damaged areas. If they don’t offer it, consider having a roofer do those fixes first.
5. What warranty do you offer, and what does it cover exactly? Get clarity on the warranty length (usually five years) and what exactly it covers (does it cover leaks or just that the shingles will stay flexible?) These warranties usually just promise that shingles will stay flexible and serviceable for 5 years. Also, ask what happens if you’re not satisfied. Will they re-treat or refund? Many companies boast satisfaction guarantees, but you need to get that in writing.
6. Will this impact my current roof warranty or insurance? See if they are knowledgeable. They will likely say it doesn’t affect insurance (maybe even helps) and that shingle warranties at that age are prorated anyway. Some might even offer in writing that if your manufacturer warranty is voided due to the treatment, they will cover what the warranty would have (Roof Maxx has indicated they’d defend homeowners if a roofing warranty claim was denied due to the treatment​). It’s good to have that discussion so you know where you stand.
7. How long has this product been used and can I see long-term results? Essentially, you’re asking for proof. They might have internal studies or examples of roofs treated 5+ years ago that are still doing well. Any data or references here will boost confidence.
8. What is the cost per square foot and how is it applied? Ensure you are getting a fair rate in line with what other homeowners are paying. They should also be able to explain the application process in a way that shows they fully understand the process (the kind of spray equipment, how many coats, how they ensure even coverage).
9. What should I expect after application? Ask if the roof will be slippery, how long to stay off it, what it will look like, and if there’s any maintenance or follow-up needed. This prepares you and also tests if they set realistic expectations (they should mention the darkening of shingles, and that you might still see some granule loss but likely less over time, etc.).
10. Are you licensed and insured? This is basic for any contractor on your property. Given they’ll be climbing on your roof, make sure they are licensed to do business in your state and have general liability and worker’s comp insurance.

By asking these questions, you not only get valuable information, but you also gauge the contractor’s honesty and knowledge. If they answer everything openly and accurately (and even acknowledge industry skepticism), that’s a good sign.

Budget Math for Homeowners

If you’re considering a rejuvenation treatment, you’re obviously trying to save money. Here’s how the math works:

• Calculate the Cost per Year of Life Added: For example, if a $2,500 treatment adds 5 years to the life of the roof, that’s $500 per year. Compare that to the cost of replacement: say $15,000 for a 25-year roof = $600 per year. On that over-simplified measure, rejuvenation treatment is cheaper. But if the treatment only added 3 years, it would be $833/yr, which is significantly more than replacement. You would need convincing evidence that you would get a full 5 extra years with the treatment but not without it in order to justify spending money on the treatment. Of course, people have different reasons for deferring a large expense, and doing so may result in other financial benefits depending on how you use that saved money over those extra years that you are able to keep it.
• How Long You Plan to Keep the Home: If you expect to live in the home only another 3-5 years, a rejuvenation treatment might carry you through without needing a new roof, which could be a huge benefit. Of course, selling a house that needs a new roof can significantly affect the sales price, but you can mention the roof was recently treated and comes with some remaining warranty, which may or may not be a plus. And some buyers may not care what condition the roof is in.
• Maintenance Bundling: You could think of a rejuvenation treatment as part of a roof maintenance package. If the contractor also cleans the roof, clears gutters, fixes flashings…those are things you might have paid for separately anyway over a 5-year span. By bundling them with the treatment, you’re getting comprehensive upkeep. A clean, well-maintained roof itself lasts longer. So some additional benefits may result from having your roof inspected, cleaned, and tuned-up as part of the process.
• Buying Time: If you can’t afford a new roof right now, a rejuvenation treatment might get you through until you can. On the other hand, delaying could mean paying future higher prices. But at least you’d have the time to plan and budget.
• Uneven Roof Deterioration: If only one area of your roof is problematic (say the south-facing slope is deteriorating faster than the north slope), you might treat the bad area and avoid a full replacement for a while.

DIY Temptation: You might wonder if you can buy a similar soy oil product and spray it yourself for less. There are some DIY roof conditioning products on the market, but there are issues. Improper application could cause more harm (uneven sealing, etc.). The cost savings might not be much after buying the equipment and the product. And climbing on a deteriorating roof with a sprayer has safety risks. Generally, DIY is not recommended for this kind of job. You’d basically be risking your roof and/or your life to save maybe $1000.

In evaluating cost vs. benefit, try to get quotes for both replacement and rejuvenation. If a roofer you trust says your roof could last “maybe five more years” and a rejuvenation quote promises to get you those five years + an additional five years with two treatments at 2/5 the cost of replacement, it may or may not make sense to do it. If a roofer examines the roof and says “honestly, you have maybe one to two years left, I wouldn’t spend your money on anything but replacement,” you should take that seriously. Maybe get a second opinion, but don’t ignore clear signs that the roof is at end of life (like widespread leaks, massive granule loss, shingles cracking and curling). If your roof is that far gone, rejuvenation treatments are likely to be a complete waste of money.

Summary & Guidance

After examining the evidence, claims, industry opinions, and real-world considerations, what’s the verdict on asphalt shingle rejuvenation treatments? Are they effective, partially effective, or not recommended? A fair conclusion is:

Asphalt shingle rejuvenation treatments appear to be partially effective in extending the life of asphalt roofs under the right conditions, but they are not a miracle cure and are not appropriate for every situation.

In other words, they do work to a degree, restoring flexibility, improving resistance to wind damage, and buying time, but only on roofs that still have some life left to extend, and only if homeowners understand their limitations. They should be viewed as a form of maintenance, not a substitute for a necessary roof replacement.

My personal opinion, after reviewing all of the information I could find, is that it looks like roof rejuvenation treatments do work to the extent that they keep shingles flexible for the promised amount of time.

I get the sense that these treatments probably typically work like this: Let’s say you have a 15-year-old roof that will probably last 25 years just the way it is (and possibly longer) and the material warranty from the roofing manufacturer expires at 15 years. You treat the roof for the first time at 15 years, then again at 20 years and 25 years old. The roof lasts 30 to 35 years. This might lead some people to think that the treatments got them an extra 15 to 20 years of service life. In my experience, roofs will generally last at least 30% longer than the full non-prorated warranty period, and often up to twice as long.

If each treatment costs around 20% of the the cost of roof replacement, and each treatment extends the roof life by 20%, the benefit isn’t really financial in the long term. The benefit lies in not having to spend all that money at once right now, and being able to put off dealing with a roof replacement. The down side is the uncertainty. There’s really no proof that a treatment will make your roof last 20% longer than the roof would have lasted without it. My father and I put an asphalt shingle roof on my parents’ house in Connecticut 35 years ago. That roof was considered a 25 year roof at the time. It’s finally getting replaced, but needless to say, it was never treated with any rejuvenation product. It lasted 40% longer than expected.

It’s just really hard to definitively say what the actual added roof life will be, and therefore whether a treatment will actually save you any money, and if it does, how much. Also, remember that a new roof comes with a material warranty and workmanship guarrantee and a treated roof doesn’t.

Key Takeaways:

• Valid Concept: The idea of re-saturating asphalt with oils is scientifically valid and test-supported. Lab results show treated shingles perform more like newer shingles in flexibility and granule retention​. So rejuvenation can slow the aging process.
• Limited Endorsement: No shingle manufacturer or major roofing body endorses these treatments. This doesn’t mean the treatments don’t work; it means the long-term proof isn’t established and manufacturers prefer you replace the roof with their new product. Homeowners who decide to try rejuvenation are essentially going off-label, relying on the rejuvenation company’s own warranty and data rather than the shingle manufacturer’s blessing.
• When to Use: The treatments are best for roofs in the early-to-mid stages of aging. Ideal candidates might be 7-15 years old (for a 25-30 year rated shingle) that are drying out but not leaking or falling apart. In these cases, rejuvenation can extend the useful life by several years, keeping the roof sound and buying time. If done proactively, it might prevent the roof from getting to the “failing” stage until very late in its lifespan.
• When Not to Use: If a roof is already failing (multiple leaks, widespread shingle deterioration, near or beyond its expected lifespan) a spray treatment is not recommended. It’s unlikely to halt the many problems of an end-of-life roof. Also, if local codes or warranty concerns are significant think twice. And obviously, don’t bother treating a roof with design flaws or installation issues that need correction.
• Partial Effect: Even on a treated roof, you must continue regular maintenance. The treatment doesn’t eliminate the need for inspections, cleaning, and occasional repairs. It just reduces the brittleness of the shingles. Other components (flashing, vents, etc.) still age normally.
• Longevity Gains: Homeowners can hope for up to five years of added life per treatment, based on warranty coverage and limited field results​. In some cases, maybe more; in others, maybe less. The “up to 15 years” claim involves re-treatment (with that additional expense) every few years.
• Cost/Benefit: For many, the economics are favorable. A couple thousand dollars now to put off a $15k expense may be worth it, especially if you funnel those savings into other urgent needs or investments. Just be sure to save up for the eventual replacement, because the clock doesn’t stop, it just ticks slower.
• No Magic for Leaks: If you have active leaks, fix them properly. Use the rejuvenation treatment afterwards to help the rest of the roof, but don’t rely on soybean oil to plug holes. That’s not what they’re meant for.
• Choose Quality: If you decide to proceed, pick a reputable service provider with good references. You want a company that will be around long enough to be able to honor the warranty if you need them to. The product itself matters (stick to known brands that have been tested). Application quality matters too. Improper application could lead to underperformance or a mess.
• Monitor Results: After treatment, keep an eye on your roof. See if you notice differences (are shingles lying flatter? fewer granules in gutters? no new cracks forming?). Continue to have the roof inspected annually. If the product doesn’t do what it’s supposed to, call the warranty department.

Ultimately, rejuvenation is a maintenance strategy, not an alternative to eventual replacement. A well-maintained roof will always outlast a neglected one. These treatments offer the homeowner another way to maintain their roof, the value being somewhere between doing nothing and doing a full replacement.

Sources

• ARMA Technical Bulletin: “Coating of Asphalt Shingles After Installation” – Asphalt Roofing Manufacturers Association​
• Ohio State Univ. & PRI Laboratory Testing on Roof Maxx (2017-2018)​
• PRI Asphalt Technologies Report for Greener Shingles (2018)
• Farm Progress: “Soy Oil to Roof Rescue” (Aug 2024) – demo of RoofRestor soy-based treatment​
• Better Business Bureau: “Roof Maxx Technologies LLC” – consumer feedback​
• Roof Maxx: Roof Maxx FAQs – warranty and insurance statements​
• Roof Rejuvenate USA: Roof Rejuvenate FAQs
• NRCA / Professional Roofing: “Myth busting: the risks and unverified benefits of field coating asphalt shingles” April 2010