Delaware Roof Replacement Cost Guide (2025 Update)

Introduction

In this article, I’ll give you the typical costs for installing a new roof in Delaware in 2025, for both residential and commercial buildings. I’ve spent years reviewing contractor bids and researching roofing costs for my clients around the country. The roof cost estimates I provide here were produced by analyzing current material prices, Delaware labor costs, and other relevant factors, including roofing project values from actual Delaware building permit data. The roof systems covered here include asphalt shingles, metal roofing, slate, tile, synthetic composite, cedar shakes and shingles, and all of the common types of low-slope commercial roofing.

Roof replacement costs in Delaware are close to the national average, with statewide construction costs typically running about 5 percent higher. Prices tend to be higher in New Castle County and the beach markets around Rehoboth and Lewes, and a bit lower in more rural parts of Kent and Sussex Counties. (Compare to national average roof replacement costs.)

Actual roof prices will vary depending on location, roof size, roof slope, complexity, and, of course, the type of roof system installed. Asphalt shingles are the most common residential roof covering in Delaware, but alternatives like standing seam metal, slate, and cedar are also seen. Commercial “flat” (low-slope) roofs typically use single-ply membranes, such as EPDM, TPO, and PVC, as well as modified bitumen or spray-applied polyurethane foam systems.

On average, Delaware residential roof replacement prices in 2025 typically range from around $6 per square foot for basic asphalt shingles to around $36 per square foot for high-end copper roofing. This means a typical 1,700-square-foot pitched roof may cost between about $10,000 and $61,000, depending on the material chosen.

Commercial roofing usually costs more than people expect, because of R-value/insulation requirements. Board insulation is normally installed as part of a low-slope roof system, and costs around $1 to $1.50 per square foot (installed) per inch of thickness while providing an R-value of around R-4 to R-6 per inch.

Commercial roof replacement prices in Delaware range, on average, from around $5 per square foot for a ballasted EPDM overlay system with no insulation included to around $18 per square foot for a 2-ply modified bitumen roof with enough insulation to meet the Delaware R-30 energy code requirement for roofs with above-deck insulation

The tables below provide cost information for all roof types and systems.

Climate Considerations for Delaware Roofs

Delaware’s climate is generally classified as humid subtropical, with some humid continental influence in the northern part of the state. Summers are warm to hot and humid, while winters are relatively mild compared with states farther north. Average annual precipitation is about 45 inches, distributed fairly evenly throughout the year, though late spring and summer often bring heavy thunderstorms. Snowfall is usually light to moderate, with northern areas around Wilmington receiving more than coastal Sussex County. Severe weather risks include strong coastal storms, nor’easters, tropical systems, and high winds, especially along the Atlantic coast and Delaware Bay.

Heating degree days do exceed cooling degree days across most of the state, but Delaware’s climate is warmer overall than states farther north. Cool roofing systems, such as reflective white membranes or coatings, are more beneficial here than in colder climates, as they help reduce cooling costs during the hot, humid summers. Asphalt shingle roofs in Delaware are prone to algae growth (Gloeocapsa magma), which results in annoying dark streaks and stains on the roof; algae-resistant shingles are strongly recommended.

Given these conditions, homeowners and property managers in Delaware should consider the following:

• Asphalt shingles are the most common and affordable option. Algae-resistant shingles are recommended in humid regions.
• Proper ventilation and underlayment are critical. Adequate attic ventilation reduces condensation, minimizes shingle overheating, helps prevent ice dams in the winter, and extends shingle life. Ice and water shield underlayment should be applied along eaves and valleys to guard against wind-driven rain and freeze-thaw damage. Improper roof/attic ventilation can void your roof warranty.
• Metal roofing performs well across Delaware. Aluminum is especially suited for coastal locations due to its corrosion resistance, while PVDF-coated aluminum or steel panels provide long-term durability and color stability.
• Slate, tile, and cedar roofing perform well when installed correctly with proper flashing and drainage. Cedar should only be used in Class A fire-rated assemblies. Copper or zinc strips can help limit algae and moss growth in shaded or damp areas.
• Insulation and air sealing are important. A properly insulated and sealed attic reduces energy costs year-round, improves comfort, and minimizes the risk of ice dams.

Things to Keep in Mind

These roof cost estimates should be fairly accurate; I make an effort to update them regularly using current material prices and labor data specific to Delaware. Keep in mind that the costs listed below are averages, and actual costs can vary significantly depending on your specific location and the size, configuration, accessibility, and condition of your particular roof.

The residential roof cost estimates provided here are for roof replacements on roofs with a 6/12 pitch and include all standard roof components (underlayment, ice & water shield, fasteners, flashing, etc.). Steeper roofs or roofs with complex designs can increase costs by as much as 30%.

Removal of an existing commercial or residential roof typically adds between $1 and $3 per square foot. For the estimates in the tables below, $1.50 per square foot for tear-off and disposal has been included in all pricing except for the “no additional insulation” commercial roof pricing, which generally indicates a roof recover project.

Table 1: Residential Roof Costs in Delaware

Table 2: Commercial Roof Costs in Delaware

For energy code purposes, all of Delaware is located in IECC Climate Zone 4. Commercial low-slope roofs with insulation installed entirely above the structural deck must provide a minimum of R-30 continuous insulation (R-30ci). These standards are established under the Delaware Regulations for State Energy Conservation Code, which is based on the International Energy Conservation Code (IECC).

The R-30ci requirement applies to both new construction and reroofing projects where the insulation is installed entirely above the roof deck. Building owners should verify compliance when planning a replacement project, since failing to meet insulation standards can delay approvals and increase long-term energy costs.

Always verify current R-value requirements with your local building department, as code requirements can change.

When performing a roof recover, these insulation requirements generally do not apply. Recover projects usually involve adding a layer of cover board over the existing system to provide a suitable substrate, followed by the new roof membrane. Roof recovery is not always permitted or advisable.

Further Reading: Roof Cost Details by Roofing Type

• Asphalt Shingle Roof Cost Guide
• Cedar Shake & Shingle Roof Cost Guide
• Copper Roof Cost Guide
• EPDM Rubber Roof Cost Guide
• Metal Roof Cost Guide
• Modified Bitumen Roof Cost Guide
• PVC Membrane Roof Cost Guide
• Shingle Roof Cost Guide
• Single-Ply Roofing Cost Guide (EPDM, PVC, TPO)
• Slate Roof Cost Guide
• Spray Polyurethane Foam Roofing Cost Guide
• Standing Seam Metal Roofing Cost Guide
• Tile Roof Cost Guide
• TPO Membrane Roof Cost Guide

About the Author

Jack Gray spent 20 years as a principal roof consultant with the Moriarty Corporation, an award-winning building enclosure consultant firm founded in 1967. Mr. Gray has worked in the roofing industry for over 25 years, with training and practical experience in roof installation, roof inspection, roof safety, roof condition assessment, construction estimating, roof design & specification, quality assurance, roof maintenance & repair, and roof asset management. He was awarded the Registered Roof Observer (RRO) professional credential in 2009. He also served as an infantry paratrooper in the 82nd Airborne Division and has a B.A. from Cornell University.