How Much Is a Roll of Roofing Felt

Roofing felt is a common underlayment that protects roofs from moisture during and after installation. Prices vary by material, weight, and size, but understanding typical costs helps homeowners budget effectively. This guide explains what influences price, what a roll covers, and practical tips for purchasing and installation in American homes.

Understanding Roofing Felt: Types And Sizes

Roofing felt, also called underlayment, comes in several forms. The most traditional is asphalt-saturated felt, measured by weight with common options of 15-pound (15 lb) and 30-pound (30 lb). Heavier rolls generally provide more durability and longer protection against wind-driven rain. In recent years, self-adhesive and synthetic underlayments have grown in popularity due to faster installation, better waterproofing, and improved tear resistance. Key factors include material composition (asphalt-saturated versus synthetic), weight grade, and whether the roll is self-adhering.

Roll dimensions typically fall into standard widths of 36 inches, with lengths that yield different coverage per roll. A single roll may cover roughly 100 to 200 square feet, depending on its exact size and material. When choosing, homeowners should balance cost against performance, roof pitch, climate, and installation method.

Typical Prices And What Affects Cost

Asphalt-saturated roofing felt generally costs less than synthetic or self-adhesive varieties, price ranges reflect quality and features. A typical 36-inch-wide roll of 15-lb asphalt felt might cost around $15 to $25 per roll in many markets. Heavier 30-lb felt often falls in the $20 to $35 per roll range. In higher-demand seasons or regional markets with higher material costs, prices can edge toward $40 per roll.

Self-adhesive and synthetic underlayments command higher prices due to installation ease and superior performance. Expect roughly $40 to $80 per roll for common 36-inch widths, with premium synthetic products or heavy-duty insulated underlayments occasionally exceeding $100 per roll. Labor-saving features, such as no-nailing installation or self-sealing adhesives, contribute to the higher price tags.

Other cost considerations include packaging units (some sellers sell by bundles), regional delivery charges, and the inclusion of vapor barriers or moisture fasteners. In areas with heavy rainfall, coastal exposure, or extreme heat, buyers might prioritize higher-grade underlayment even if the upfront cost is greater, due to long-term durability.

How Many Rolls Do You Need

Calculating the number of rolls requires estimating roof surface area in square feet and knowing each roll’s coverage. One standard roll of 36-inch-wide felt typically covers about 100 to 120 square feet for 15-lb felt, and closer to 100 to 180 square feet for 30-lb or synthetic underlayments, depending on the exact roll length. A practical rule is to measure the roof’s plan area in squares, where one square equals 100 square feet. Then divide the total square feet by the roll coverage. Always add a 10% to 15% waste factor for overlaps and mistakes, especially on complex roof lines.

For example, a simple gable roof measuring 1,500 square feet would need roughly 13 to 15 rolls of standard 36-inch 15-lb felt (assuming 100–120 sq ft per roll), plus extra for hips, valleys, and overhangs. If using self-adhesive or synthetic underlayment, the same roof area might require fewer rolls due to larger coverage per roll or quicker installation, but higher per-roll cost.

Tips For Buying And Installing

Effective purchasing starts with accuracy. Measure roof area carefully, account for pitch and waste, and verify the exact roll length and coverage from the supplier. Compare prices per square foot rather than per roll to get an apples-to-apples comparison across brands and types.

Installation considerations influence value. Asphalt-saturated felt requires nails or staples and precise laps to prevent leaks. Self-adhesive underlayment eliminates nailing in many areas but may demand specific weather conditions for proper adhesion. For steep pitches or high-wind regions, a more robust underlayment offers better protection and peace of mind.

Overlap guidelines are essential: typically a 2-inch to 4-inch lap for felt and a 2-inch seam for synthetic or self-adhesive sheets. In certain climates, additional fasteners or adhesives are recommended at eave edges and roof penetrations. Always follow manufacturer instructions and local building codes.

Storage and handling affect performance. Keep rolls flat, protected from moisture, and away from direct sunlight to prevent premature aging. When transporting, secure rolls to prevent rolling or tipping, which can damage the paper surface or cause wrinkles in the underlayment once installed.

Where To Buy And Related Costs

Roofing felt is widely available at home improvement stores, lumberyards, and roofing distributors across the United States. Online retailers also offer competitive pricing and bulk discounts. Local availability can impact price due to shipping, taxes, and delivery options.

Consider total project costs: the price of the underlayment is just one part. Include labor (if hiring a contractor), tools (such as a utility knife, nails, and staple gun), and any fasteners required by the underlayment type. In DIY scenarios, purchasing an extra roll or two is prudent to accommodate mistakes and cuts for complex roof shapes.

Pro tip: Look for bundled deals that include underlayment and necessary fasteners, and check for warranties on the product. Some manufacturers offer extended warranties on their synthetic underlayments, which can add long-term value even if upfront costs are higher.

Summary Of Key Points

• Types: asphalt-saturated felt (15 lb, 30 lb) vs. synthetic/self-adhesive underlayments.
• Price range: 15-lb felt typically $15–$25 per roll; 30-lb felt $20–$35 per roll; self-adhesive/synthetic $40–$80 per roll.
• Coverage: most rolls cover roughly 100–180 square feet, depending on weight and length.
• Calculation: determine roof area in squares (100 sq ft per square) and divide by roll coverage; add 10–15% waste.
• Installation: follow product guidelines for laps and overlaps; consider climate and roof pitch when selecting underlayment.