EIFS (Exterior Insulation and Finish System): Facts & Tips

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EIFS Cladding Systems Overview

“EIFS” stands for “Exterior Insulation and Finishing Systems” and it’s an extremely popular exterior wall covering for both commercial and multi-family residential construction. EIFS was first used on masonry buildings in the 1960’s, but today you can find it on wood- or steel-framed buildings as well.

EIFS is a multi-layered cladding system that provides both insulation and weatherproofing, along with a variety of color options and a design flexibility that permits various decorative trim styles and architectural details. EIFS has become a popular alternative to traditional cladding materials like brick veneer, stucco, and stone because of its superior energy efficiency, design variability, and relatively simple installation process.

But the fact that it costs less than traditional materials has probably done more to drive its growing prevalence than anything else.

The basic components of an EIFS system include insulation board, a base coat, reinforcing mesh, and a finish coat. Current EIFS installations typically incorporate a dedicated water-resistive barrier (WRB) and/or drainage layer behind the insulation board to help mitigate moisture accumulation within the system.

The insulation layer uses standard polystyrene or polyisocyanurate board insulation, which is attached to the exterior wall surface, the studs, or the wall sheathing with adhesive and/or mechanical fasteners.

The base coat is a water-resistant, cementitious material applied to the surface of the insulation board. The reinforcing mesh is embedded into the base coat.

The reinforcing mesh is typically made out of glass fiber. It provides additional strength and durability to the system by distributing the stresses caused by temperature changes and wind loads across the entire system. In particular, the reinforcement mesh is vital in preventing the waterproof coating layers from cracking and splitting at the joints between the insulation boards.

The finish coat is the main waterproofing layer for an EIFS system. It is applied over the base coat/reinforcing mesh, and it serves as the visible outer layer of the system. It can be colored and textured to produce a wide variety of different appearances. The basic chemistry of the standard finish coat on an EIFS system is acrylic co-polymer.

Early EIFS installations (sometimes called “barrier EIFS”) did not always include a drainage plane. These older systems performed best on masonry substrates but were more vulnerable to moisture problems when used on wood- or steel-framed walls without an additional drainage layer. Today, building codes often require a water-resistive barrier and proper flashing details for EIFS to help manage moisture effectively.

How to Tell If a Building Has EIFS

One of the easiest ways to check if an exterior finish might be EIFS is the “knock test.” If you gently tap on the wall surface with your knuckles, EIFS often produces a hollow or slightly soft sound, as opposed to the hard, solid sound you’d hear with traditional stucco or brick. This happens because of the foam insulation behind the coating.

Look closely at trim and decorative elements. EIFS often has thick decorative features around windows, doors, and corners without the weight or supporting elements you’d expect from real masonry. If the trim appears especially thick or seems too light to be formed of concrete or wood, that’s a clue that you might be looking at EIFS.

Inspect the surface for telltale horizontal lines. Sometimes you can see faint lines where the foam insulation boards meet, especially if the coating has aged or if repairs were made at some point. These lines can appear as hairline cracks or slight ridges.

Check the window and door openings. In traditional stucco, the stucco itself is often extended right up to the frame. In EIFS installations, there might be a trim piece of foam around the opening, coated in the same finish as the rest of the wall, or there may be a visible sealant joint between the foam edge and the window or door frame.

Look at the wall thickness at penetrations. If you can see a cross-section of the cladding (for instance, around vents or lighting fixtures), EIFS typically shows a distinct layer of foam insulation (usually white polystyrene, but sometimes yellowish or off-white polyisocyanurate). Traditional stucco systems or masonry do not have that foam layer.

Consult building records or plans if available. They might specifically list “EIFS” or “Exterior Insulation and Finish System.” Local building departments often keep construction permit documents that can confirm what type of exterior system was installed.

If you’re unsure whether a building has EIFS or a similar system, having a qualified professional inspect it is the best way to be certain.

Lifespan of EIFS

The service life of EIFS can vary quite a bit, but with proper installation, consistent maintenance, and timely repairs, many EIFS systems can last 30 to 50 years, or even longer. A few key factors influence this range:

1. Installation Quality:
   • A properly installed EIFS will have flashing, integrated water-resistive barriers, and fully adhered or mechanically fastened insulation boards.
   • Poor workmanship can lead to moisture intrusion, delamination, and damage to underlying substrates, all of which can severely shorten the system’s life.
2. Climate and Exposure:
   • EIFS in regions with extreme temperature swings, high humidity, or frequent wind-driven rain may require more frequent inspections and maintenance.
   • UV exposure and pollution can gradually degrade the finish coat over time, though high-quality acrylic finishes typically offer good resistance.
3. Maintenance Practices:
   • Regular inspections, routine cleaning, and prompt sealing of cracks or gaps can help prevent moisture problems.
   • Proactive care in addressing any small issues before they escalate is a major driver in extending the lifespan of EIFS.
4. System Upgrades and Renovations:
   • Many older “barrier” EIFS installations have been retrofitted or upgraded to modern, drainable systems to reduce moisture risk. Such upgrades can greatly extend the overall lifespan of the assembly.
   • Periodic recoating with compatible finish products can refresh the appearance of EIFS and prolong its waterproofing capabilities.

If all of these factors are managed properly, an EIFS system can remain structurally sound and visually appealing for several decades.

EIFS Manufacturers List

The following reputable EIFS manufacturers typically provide detailed installation guidelines, system component specifications, and warranties, which help ensure proper EIFS performance and service life.

1. Ashland Inc.
   • A global specialty materials company. Some of its divisions provide additives and resins used in EIFS formulations.
2. BASF
   • A major chemical producer offering energy-efficient building envelope solutions, including EIFS products under various brand names.
3. Dryvit Systems, Inc.
   • A leading manufacturer of EIFS systems, known for its extensive range of finishes and insulation options.
4. Energex, Inc.
   • Provides high-performance EIFS solutions and coatings designed to reduce energy consumption.
5. Master Wall, Inc.
   • Known for multiple EIFS product lines and a strong focus on training and technical support for proper installation.
6. Parex USA, Inc.
   • Offers a diverse portfolio of building solutions, including EIFS, stucco, and other façade technologies, under brands like Parex, El Rey, and Teifs.
7. Senergy (Now owned by Sika)
   • A well-established EIFS brand, integrated under Sika’s broader building envelope product range; notable for its variety of finish options.
8. Sto Corp.
   • A global company specializing in high-quality EIFS, stucco, and architectural coatings.

Benefits of EIFS

One of the main benefits of an EIFS system is the improved thermal performance (“insulation” being the “I” in EIFS) of the walls compared to more traditional cladding systems that are intended to weatherproof but not necessarily insulate. Because it’s on the outside of the wall, the insulation board used in EIFS can provide continuous insulation over the entire wall surface, which reduces thermal bridging (at wall studs, for instance).

A typical EIFS installation will add at least R-5 to the overall R-value of a wall system. EIFS systems provide around R-4 to R-5 per inch of expanded polystyrene (EPS) foam, or slightly higher if polyiso boards are used. The thickness of the insulation board can be increased to meet specific energy code requirements or design preferences. This continuous insulation can also help reduce the risk of condensation within the wall assembly.

Another benefit of EIFS is its design flexibility. The finish coat can be customized to produce a desired color and texture; it can also be finished to resemble a variety of materials, including brick, stucco, or stone. This flexibility allows for a wide range of design options. In addition to texture and color choices, detailed architectural features such as cornices or decorative trim can be formed using EIFS components.

A significant benefit of EIFS (if money is a critical concern for the project, and it usually is) is its relatively low cost. As an example, according to the EIFS Industry Members Association in 2016: “EIFS is one of the most economical systems available, with an estimated material cost per square foot at $0.86 and installation cost of $5 to $6, which compares with the cost per square foot for brick at $1.25 with an installation cost of $8.50.” While these figures may vary by region and fluctuate over time, they illustrate the general cost advantage of EIFS over other cladding systems.

Drawbacks of EIFS

One of the main drawbacks of an EIFS system is its potential for moisture infiltration if not properly installed or maintained. Early “barrier” EIFS designs, in particular, did not always incorporate a drainage plane. As a result, any water that found its way behind the system could become trapped, leading to potential mold growth and damage to underlying sheathing or framing.

Another concern with EIFS is its vulnerability to impact damage. The thin exterior finish and the underlying foam insulation can be susceptible to dents or punctures if struck by heavy or sharp objects, so care must be taken in high-traffic and building service areas.

Proper installation and detailing are critical for EIFS performance, and this can drive up labor costs if specialized contractors are required. Inadequate flashing, sealing, or moisture barrier detailing often leads to failures in the system over time.

Some local building codes have introduced additional requirements – such as using a drainage-type EIFS system rather than a simple barrier assembly – to address moisture issues. While this greatly improves the system’s moisture-management capabilities, it may also increase the overall complexity and cost of installation.

EIFS Issues

Common Issues with Exterior Insulation and Finish Systems

1. Impact Damage: The exterior finish and foam insulation layer are relatively soft and can be dented or punctured by hail, errant golf balls, lawn equipment, or other impacts. Regularly checking for damage and promptly repairing any punctures is essential to prevent moisture intrusion.
2. Joint and Flashing Failures: EIFS relies heavily on proper flashing at penetrations (e.g., windows, doors, vents) and transitions (e.g., roof-to-wall junctions). If these details are not properly sealed or maintained, water can quickly bypass the finish layer and enter the wall assembly. Sealants at joints also deteriorate over time and must be inspected and replaced as needed.
3. Difficulty Detecting Moisture Intrusion: Unlike some cladding systems where water damage is more apparent, moisture can travel behind an EIFS assembly without showing obvious external signs until the damage becomes severe. Periodic inspections, moisture testing, or infrared imaging can help identify hidden problems early.
4. Pest Infestation: In some regions, pests such as termites or carpenter ants can tunnel into or behind the foam insulation if it remains damp or is left exposed at the base of the wall. Installing termite shields or ensuring the insulation does not extend below grade can help mitigate this risk.
5. Vapor Barrier Concerns: Because EIFS can act as a vapor barrier, it’s important to ensure that the overall wall assembly is properly designed to manage moisture vapor coming from the interior of the building. This is especially critical in climates with significant seasonal swings in temperature and humidity.

Proper installation and maintenance are necessary for good long-term performance of an EIFS system. You need someone who knows what they’re doing when it comes to installing and repairing EIFS. Improper installation can easily lead to water intrusion (leaks) and other moisture-related issues, which can compromise the performance of the system and even possibly lead to structural damage to the building.

I once discovered that a contractor had installed an EIFS system to serve as a screen wall on a roof. First they attached gypsum roof board (basically water-resistant sheetrock, which is by no means a waterproof material) to galvanized steel support posts using basic drywall screws.

Then they applied a full EIFS system to the exterior-facing side of the sheetrock to produce a rooftop equipment screen that was around 200 feet long and 6 feet high. They left the inside-facing side of the sheetrock exposed to the weather.

When the whole thing started to fall down in giant sections about two months later, the property manager hired us to investigate why his screen wall was falling down. The inspection took about five minutes and my report was pretty short. Wet sheetrock simply falling off the screws. Catastrophic installation defects. Etc.

I have no idea why that thing was installed like that. Maybe it was a case of an architect insisting on something that the contractor knew wouldn’t work but he installed it as specified anyway. Maybe the installers just did what they were told and nobody realized what was going to happen. Whatever it was, you can see that it’s important to hire a qualified contractor (and specifier) who knows what he’s doing when it comes to construction best practices in general, who has experience in EIFS installation, and who will follow the EIFS manufacturer’s recommended installation guidelines.

EIFS Maintenance

Proper maintenance is also extremely important for maximizing the useful service life of an EIFS system. Regular inspections and cleaning can help prevent leaks and other issues. Small cracks often develop in the outer surface of EIFS no matter how well it was installed. Building settlement is a common cause of cracks, and there’s no way for the EIFS applicator to prevent that. These cracks will have to be repaired when they show up.

Inspections should be performed twice yearly and should focus on finding small cracks and then immediately getting them repaired. Exterior building sealant (caulk) that matches the color of the EIFS is commonly used for temporary repairs, but proper repairs should eventually be made (usually once there’s enough repair work for it to make financial sense to call a professional). Moisture can enter even through hairline cracks over time, so addressing them sooner rather than later helps reduce the risk of bigger problems happening.

EIFS systems tend to be far more susceptible to moisture intrusion than traditional cladding systems. The insulation board (especially polyiso board) can easily absorb any water that makes it past the surface coating, and it can hold that moisture within the system for a long time. You don’t want that.

In properly-installed “drainable” EIFS assemblies, there will be an intentional gap or drainage plane behind the foam insulation to manage any water that might get in. This reduces the likelihood of long-term moisture entrapment. But even these systems can have problems if they are installed incorrectly or if maintenance is neglected.

With proper installation and maintenance, EIFS can be a high-performance cladding system that will improve the energy efficiency and complement the appearance of your building while reducing construction costs.

Proper Maintenance Practices for EIFS

1. Regular Inspections:
   • Conduct thorough visual inspections of all EIFS surfaces at least twice a year, preferably in the spring and fall. Look for cracks, gaps in sealant, evidence of moisture intrusion, thin or worn-down coatings, or any visible damage.
   • Pay particular attention to vulnerable areas such as windows, doors, penetrations, and roof-to-wall transitions, as water commonly enters at these points.
2. Cleaning the Surface:
   • Gently clean the EIFS surface periodically to remove dirt, pollutants, and biological growth (mold, mildew, or algae).
   • Use low-pressure water spray or a soft-bristled brush to avoid damaging the finish coat. High-pressure washers can erode or puncture the surface and should be avoided unless recommended by the EIFS manufacturer.
   • Mild detergents may be used, but confirm with the system manufacturer’s guidelines before applying any cleaning agents.
   • A common cleaning solution involves 1–2 cups of trisodium phosphate (TSP) per gallon of warm water, plus 1/2 to 1 quart of bleach to kill mold or algae. Apply this solution to the surface of the EIFS, allow to soak for 15–20 minutes, then gently rinse.
   • Always test a small area first to ensure the cleaner won’t discolor or damage the finish.
3. Sealant and Joint Maintenance:
   • Inspect sealants around windows, doors, vents, and expansion joints. These sealants can degrade over time due to UV exposure or movement in the building.
   • Replace any failing or missing sealant immediately to prevent any water from getting into the EIFS.
   • Always use a sealant that is compatible with the EIFS finish, typically one recommended by the EIFS manufacturer or a manufacturer-approved contractor.
4. Crack Repairs:
   • Small cracks can appear over time due to building movement, thermal expansion and contraction, or normal building settlement.
   • Seal hairline cracks promptly with a recommended exterior sealant to keep moisture out until a professional can perform a more permanent repair.
   • For larger cracks, contact an experienced EIFS contractor. They may need to cut out and replace a small area of foam insulation and base coat in order to maintain the proper reinforcement mesh overlap.
5. Check Flashing and Drainage Systems:
   • Verify that all flashing and drainage components are intact, correctly positioned, and functional (not blocked).
   • Ensure that gutters and downspouts are functioning properly and directing water away from the wall. Clogged or damaged drainage can increase the risk of water infiltration behind the EIFS.
   • If the system includes weep holes or other drainage paths, keep them clear of debris to allow water to escape.
6. Protect Against Impact Damage:
   • EIFS can be more prone to punctures or dents from impacts (e.g., yard equipment, ladders, or hail).
   • If the system is installed near ground level or in high-traffic areas, consider installing protective barriers or instructing building occupants and maintenance personnel to take extra care to avoid damaging the surface.
   • Promptly repair any impact damage to keep water out of the system.
7. Professional Evaluations:
   • If you suspect hidden damage or larger issues, consult a qualified EIFS inspector or contractor. They can perform moisture testing or infrared thermography to detect problems within the system.
   • Keep records of all maintenance and repairs. This documentation can help with warranties and can be valuable if serious issues develop or if the property is sold in the future.

Proper Roof-to-Wall EIFS Tie-In and Flashing Installation

When an EIFS-clad wall meets a roof surface, careful attention to flashing and waterproofing details is essential to prevent moisture intrusion and damage. This is a general guide on how to properly tie new roofing into a rising EIFS wall.

1. Determine the Cut Line and Remove the Lower Portion of the EIFS:
   • Identify the height to which the new flashing and any necessary counterflashing will be installed (typically this is at least 8 inches above the roof surface, though local code and manufacturer requirements may dictate a different dimension).
   • Use a carefully-adjusted circular saw or sharp utility knife to cut a clean horizontal line through the EIFS coating and insulation along your line. Do not cut all the way through the insulation, to avoid damaging the wall.
   • Carefully remove the insulation and any embedded mesh in the area below this line to expose the substrate or sheathing beneath.
   • Dispose of all removed EIFS materials properly and inspect the exposed substrate for signs of moisture damage or deterioration. Make any necessary repairs or replace damaged sheathing before proceeding.
2. Install the Base Flashing or Roof Termination Flashing:
   • At the intersection of the roof and the wall, install an appropriate base flashing that extends up the wall so that it will be tucked behind the reinstalled EIFS.
   • For low-slope or flat roofs, this flashing is often a membrane (such as modified bitumen, TPO, or EPDM), depending on the roof type. For pitched roofs, metal step flashing or continuous flashing may be used.
   • Ensure that the flashing is properly tied into the roofing to prevent water infiltration under the roofing membrane or shingles.
   • Bring the flashing up the wall to the height above the roof surface that is recommended for that particular flashing material. Leave enough room to properly terminate the top edge of the flashing.
3. Install Counterflashing or Termination Bar:
   • For low-slope roofing membranes, after the base flashing is in place, a counterflashing (often metal) or termination bar is typically installed along the top edge of the base flashing.
   • If using metal counterflashing, it should be inserted behind (or otherwise integrated with) the new or existing water-resistive barrier (WRB) or sheathing tape. In some cases, the WRB can be lapped over the top edge of the counterflashing to help direct water away from the wall cavity.
   • Seal the top edge of the counterflashing or termination bar with a high-quality, exterior-grade sealant. This helps create a secondary line of defense against water intrusion.
4. Reinstall or Replace the Bottom Edge of the EIFS:
   • Using the same type and thickness of insulation board as the original system, cut new pieces to fit the area you removed.
   • Attach the insulation boards according to the EIFS manufacturer’s guidelines – typically with adhesive, mechanical fasteners, or both. Be sure not to penetrate the flashing itself, unless manufacturer-approved flashing fasteners or details are used.
   • Embed reinforcing mesh in a new base coat applied to the insulation board, overlapping the existing mesh and base coat by the manufacturer’s minimum required distance (often 2–4 inches or more). This overlap ensures a continuous reinforced layer.
   • Once the base coat has cured, apply the finish coat, matching the existing texture and color as closely as possible. Carefully feather and blend the new finish into the old so the repair is as seamless as possible.
5. Ensure Proper Drainage and Ventilation:
   • As you reconstruct the bottom edge of the EIFS, maintain the recommended gap (at least 2 inches) between the bottom of the EIFS system and the surface of the roof to allow water to drain off the roof and to keep the EIFS from wicking moisture.
   • If your particular system requires weep or drainage features (“drainable EIFS”), ensure that the path for water drainage remains open and unobstructed.
6. Inspect and Maintain Regularly:
   • Perform routine inspections, especially around roof-to-wall transitions, to check for cracking, delamination, or sealant failures.
   • Promptly address any cracks, gaps in sealant, or other signs of potential water entry.

Recommended Flashing Materials

• Metal flashing (aluminum, galvanized steel, or stainless steel) is commonly used for counterflashing.
• Roof membrane materials (TPO, EPDM, modified bitumen) are typical for low-slope roofs; these should be adhered or mechanically fastened per the roofing manufacturer’s instructions.
• A high-quality sealant should be used at any termination bar and lap seams as a secondary water barrier.

Why cutting out the bottom of the existing EIFS may be necessary

• Flashing must extend behind the EIFS to effectively prevent moisture from seeping into the wall assembly. If the existing EIFS is not currently terminated high enough above the roof line, you will not have enough space to properly lap or integrate the flashing.
• Cutting out and then re-installing the EIFS in this area is often the most straightforward way to achieve a proper installation.

Key Points

• Always follow the EIFS manufacturer’s written instructions and the roofing manufacturer’s guidelines for roof-to-wall transitions.
• Cutting out and replacing the lower portion of EIFS allows room for proper flashing integration, preventing hidden moisture issues.
• Check that all sealants, fasteners, and flashing accessories are compatible with both the roofing and the EIFS system.
• Regular inspections and maintenance will help keep this critical roof-to-wall interface watertight over the long term.

EIFS References

1. General: What is EIFS? See this “About EIFS” page at the website of the EIFS Industry Members Association.

2. General: “EIFS, Architecture, And The Sustainable Design Revolution“ is heavy on the LEED information, but is also worth reading for the general EIFS info that it provides. It’s on the Whole Building Design Guide site, which is maintained by the National Institute of Building Sciences.

3. Building Codes: See the section of the 2021 International Residential Code that covers EIFS on the UpCodes website: Section 1407 Exterior Insulation and Finish Systems (EIFS)

4. Building Codes: See the section of the 2021 International Residential Code that covers EIFS on the UpCodes website: R703.9 Exterior Insulation and Finish System.

5. Inspection of EIFS: Some brief inspection guidelines are available on the technical bulletins library page on the Senergy website.

6. Technical: For a look at how an EIFS system is put together, check out the construction details available on the Senergy website.

7. Technical: Repair and Maintenance of EIFS: A very good EIFS repair and maintenance guide is provided by the Sto Corporation on their website.

8. Technical: Technical literature on various EIFS components. On the Parex website. This is only an example and other products and brands may be different.