A roll of roofing felt typically costs about $20 to $50 for traditional asphalt-saturated felt, while a larger synthetic underlayment roll often costs roughly $50 to $150 or more. The exact price depends on roll coverage, material, brand, and retailer. Because rolls cover different areas, comparing the price per 100 square feet—not just the price per roll—is the best way to estimate a roofing project’s material cost.
Typical Roofing Felt Prices
Roofing felt prices vary by product and location. Traditional felt is usually sold in 15-pound or 30-pound grades, while synthetic underlayment is sold in larger, lighter rolls. The ranges below are useful shopping estimates, not guaranteed quotes; local inventory, product specifications, and delivery fees can change the total.
| Underlayment type | Typical roll coverage | Common price range | Approximate cost per 100 square feet |
|---|---|---|---|
| 15-pound asphalt-saturated felt | About 400–432 sq. ft. | $20–$40 | $5–$10 |
| 30-pound asphalt-saturated felt | About 200–216 sq. ft. | $25–$50 | $12–$25 |
| Synthetic roofing underlayment | Often about 1,000 sq. ft., but varies | $50–$150 or more | About $5–$15 or more |
These figures refer to the underlayment itself, before taxes, fasteners, shipping, or labor. Retail listings may use different roll sizes and product names, so the package label is more reliable than a general price estimate. Some products sold as roofing felt are asphalt-saturated organic or fiberglass sheets; synthetic underlayment is a different material, even though shoppers may compare it with felt for the same roofing application.
What Affects the Cost of a Roll of Roofing Felt?
Material and product type
Traditional asphalt-saturated felt is often the least expensive option per roll. Synthetic underlayment generally costs more upfront, but a roll may cover substantially more area and weigh less. Some synthetic products also offer features such as greater tear resistance or a textured walking surface. Those features vary by product and do not make every synthetic option suitable for every roof.
Specialty underlayments can cost more than basic felt. Examples include self-adhering products for vulnerable roof areas, high-temperature underlayments, and products designed for particular roof coverings. These should not be treated as interchangeable with ordinary felt. The roof covering manufacturer’s installation instructions and local code requirements determine which materials are appropriate.
Weight and coverage
“15-pound” and “30-pound” are familiar names for traditional felt grades. They do not mean that every roll weighs exactly 15 or 30 pounds today. Product construction and roll dimensions can vary, and manufacturers may identify products by a grade or type rather than an exact roll weight. A 30-pound roll commonly covers about half as much as a 15-pound roll, so its higher price does not automatically mean it is more expensive for the same area.
Coverage figures are also not the same as the area a roof can cover after installation. Underlayment is overlapped at seams, and additional material may be needed at eaves, valleys, hips, ridges, and other details. Roof shape and the installation instructions affect how much usable coverage remains.
Brand, retailer, and location
Prices can differ between home-improvement stores, roofing suppliers, and online sellers. A lower online price may be offset by freight or delivery charges, particularly for bulky materials. Regional demand, stock levels, and local building practices can also affect selection and price. For a meaningful comparison, shoppers can check the price, roll coverage, product specification, and delivery cost together.
How Many Rolls Does a Roof Need?
Roofing material is often estimated in squares. One roofing square equals 100 square feet of roof surface—not 100 square feet of a home’s floor plan. A roof’s actual area depends on its dimensions, slope, and layout, so a contractor or accurate roof measurement is preferable to estimating from the house’s footprint alone.
As a simple starting point, divide the roof’s measured surface area by the coverage printed on the roll. Then account for overlaps and cutting waste. For example, a roof with 1,000 square feet of surface would require approximately three rolls of 15-pound felt if each roll covers 432 square feet before installation losses. A 216-square-foot roll of 30-pound felt would require about five rolls for the same area before losses.
Actual quantities can be higher. A roof with multiple valleys, dormers, hips, or other complex details may generate more offcuts than a simple gable roof. The required overlap also depends on the product and roof pitch. Rather than applying a universal waste percentage, the most accurate estimate follows the product’s installation instructions and the roof’s specific layout.
Example material estimate
Suppose a roof has 1,500 square feet of measured surface. At 432 square feet per roll, the basic calculation is 1,500 divided by 432, or about 3.5 rolls of 15-pound felt. That means at least four rolls would be needed before accounting for overlap, cuts, or damaged material. If the roof design requires more, the project may need an additional roll.
For budgeting, multiply the number of rolls by the local price per roll, then add fasteners, delivery, and any other specified materials. The estimate covers underlayment only; it does not include shingles, flashing, roof-deck repairs, tear-off, or installation labor.
Roofing Felt Compared With Synthetic Underlayment
Traditional felt and synthetic underlayment both serve as layers beneath many roof coverings, but they differ in construction and handling. Asphalt-saturated felt is a long-established product. Synthetic underlayment is typically made from a polymer-based material and is available in a range of weights, surface textures, and performance specifications.
| Consideration | Traditional felt | Synthetic underlayment |
|---|---|---|
| Initial roll price | Often lower | Often higher |
| Roll coverage | Commonly smaller | Often larger; check the label |
| Handling | Can wrinkle or tear if mishandled | Many products are lighter and more tear-resistant, but specifications vary |
| Compatibility | Depends on roof covering and installation instructions | Depends on product, roof covering, and installation instructions |
Price alone does not determine the best choice. A larger synthetic roll may reduce the number of rolls or seams, but it may have a higher upfront price. Traditional felt may be economical for a suitable project. The decision should account for the roof covering, slope, weather exposure during installation, local requirements, and the manufacturer’s instructions.
Underlayment is not a substitute for proper flashing, drainage, or a sound roof deck. Nor should a product be assumed to provide a particular amount of temporary weather protection unless its documentation says so. Different underlayments have different limitations, including requirements for fastening, exposure time, and installation conditions.
How to Compare Roofing Felt Prices
- Confirm the product type. Check whether the listing is for 15-pound felt, 30-pound felt, synthetic underlayment, or a specialty membrane.
- Compare stated coverage. Use the roll’s printed square footage, not the number of rolls alone.
- Calculate cost per 100 square feet. Divide the roll price by its coverage and multiply by 100. This makes products with different roll sizes easier to compare.
- Check installation requirements. Review the product instructions and the roofing material manufacturer’s requirements before buying.
- Include the full purchase cost. Add tax, fasteners, delivery, and any required accessories to the estimate.
- Plan for cuts and overlaps. Use measured roof dimensions and the specified overlap to determine the order quantity.
For example, a $30 roll covering 432 square feet costs about $6.94 per 100 square feet before installation losses. A $60 roll covering 1,000 square feet costs about $6 per 100 square feet. In that comparison, the more expensive roll has the lower material cost per unit of coverage—but the products still need to be suitable for the same application before price becomes decisive.
Can Roofing Felt Be Installed on Any Roof?
No single underlayment is right for every roof. Requirements can depend on the roof covering, slope, climate, and local building code. Asphalt shingles, metal roofing, and other systems may have different underlayment specifications. Some roof assemblies require specific products in certain areas, while some materials may not be approved for a particular use.
In the United States, building codes are adopted and enforced by state or local jurisdictions, and requirements can differ. The International Code Council publishes model codes that jurisdictions may adopt or amend; the locally adopted code is the one that matters for a project. Product labels and installation instructions should also be checked, especially when a roof covering warranty depends on following the manufacturer’s specifications.
For code or product questions, a local building department or qualified roofing contractor can help confirm the required underlayment and installation method. This matters particularly for low-slope roofs, areas exposed to wind-driven rain, and projects involving unusual roof coverings or specialty membranes.
Where to Check Current Prices and Specifications
Prices change, so shoppers should verify current listings with local home-improvement retailers and roofing suppliers. Retail product pages can help confirm the roll size, coverage, and listed price, but product availability and delivery costs may vary by ZIP code. A manufacturer’s product data sheet is usually a better source for technical details than a short retailer description.
For broader guidance, the Owens Corning roofing installation resources and GAF’s roofing underlayment information explain product considerations and installation context. These resources do not replace the instructions for the specific product selected or local code requirements.
Quick Answer: How Much Is a Roll of Roofing Felt?
A typical roll of traditional roofing felt costs around $20–$50, with 15-pound felt often at the lower end and 30-pound felt often costing more per roll. Synthetic underlayment commonly costs about $50–$150 or more, depending on its coverage and features. To estimate a project accurately, compare each product’s cost per 100 square feet and calculate the quantity using the roof’s measured surface area, overlap requirements, and installation instructions.