Quick Answer: Roofing underlayment typically runs $0.30 to $2.50 per square foot material as of 2026, and $1.00 to $4.00 per square foot installed. The range is wide because underlayment covers everything from a 15 pound felt roll on a shed to a self adhering peel and stick membrane on a tile roof. Treat the ranges below as a starting point and pull live quotes from your supplier for the bid date.
What You Are Actually Pricing
Underlayment is the actual waterproof layer under the visible roof covering, and you bid it by type. Asphalt saturated organic felt (15 pound and 30 pound) is the legacy product, cheap and still used on sheds and low cost shingle roofs. It runs $0.30 to $0.50 per square foot material, $1.00 to $1.75 installed. Synthetic underlayment (polypropylene or polyethylene woven sheet, often called by brand names like Titanium, RhinoRoof, and DeckArmor) is the modern residential standard, lighter, stronger, and slip resistant, and runs $0.40 to $0.90 material, $1.25 to $2.25 installed. Self adhering modified bitumen membrane (peel and stick, often called ice and water shield around eaves and valleys) is the premium, $0.80 to $2.50 material, $2.00 to $4.00 installed. High temperature self adhering membrane (for under metal and tile that gets hot) costs more than standard, $1.20 to $2.50 material. Specialty breathable membranes (for unvented assemblies and standing seam under metal) run $0.80 to $2.00.
The unit is the roll. Felt and synthetic rolls cover 10 squares (1,000 square feet) at typical exposure, ice and water rolls cover 2 squares (200 square feet). You buy per roll and convert your roof area to roll count. Underlayment is the layer that gets walked on, so the type and the rating matter for the warranty on the roof above it.
What Drives the Price
Type and chemistry. Felt is the cheapest because it is paper saturated in asphalt. Synthetic costs more because it is a woven polymer that does not tear, does not wrinkle when wet, and resists UV for weeks during a long roof install. Self adhering membrane costs the most because it carries the asphalt and the adhesive and the release liner, all in one roll. The price step from felt to synthetic is small; the step from synthetic to peel and stick is 2 to 4 times the unit cost.
Thickness and weight. Felt is sold by weight per square (15 pound and 30 pound). Synthetic is sold by mil thickness (20 to 40 mil) and by tensile strength. Self adhering membrane is sold by mil of membrane plus mil of adhesive, often 40 mil membrane with 25 mil adhesive. Thicker and heavier costs more, and most warranties require a minimum thickness to issue. Quoting 20 mil synthetic when the spec calls 40 mil is a 30 to 40 percent miss.
UV and exposure rating. Standard synthetic is rated for 30 to 60 days of UV exposure before the roof covering goes on. High exposure synthetic (90 to 180 days, sometimes called a temporary roof) costs more because it has UV stabilizers that keep it from breaking down in the sun. On long jobs where the roof stays open for months, the high exposure rating is not optional.
Temperature rating. Self adhering membrane is rated for the surface temperature it will see under the finished roof. Standard membrane is rated to about 200 degrees Fahrenheit and is fine under shingles. Under metal and tile, the surface can hit 250 degrees or more, and standard membrane will melt and leak adhesive. High temperature membrane (SBS modified, granulated surface) is required and runs 20 to 40 percent more.
Manufacturer and warranty tie. GAF, Owens Corning, Carlisle, Henry, and Grace are the major brands. Roofing system warranties from the shingle or metal manufacturer often require their own underlayment brand in the system, so the underlayment is not interchangeable once a system warranty is on the line.
Region, freight, and volume. Underlayment is bulky. A pallet of ice and water is heavy and takes space. Freight is a line on distant jobs, and volume pricing is real. A 20 roll order pays list; a 200 roll commercial job gets 15 to 25 percent off plus freight consolidation. Do not bid a big job off the small order sheet.
Typical Price Ranges by Type
- 15 pound asphalt felt: $0.30 to $0.40 material, $1.00 to $1.50 installed.
- 30 pound asphalt felt: $0.40 to $0.50 material, $1.25 to $1.75 installed.
- Synthetic underlayment, 20 to 30 mil, standard exposure: $0.40 to $0.70 material, $1.25 to $2.00 installed.
- Synthetic underlayment, 40 mil, high exposure (90 to 180 day UV): $0.60 to $0.90 material, $1.75 to $2.50 installed.
- Self adhering peel and stick, standard temperature: $0.80 to $1.50 material, $2.00 to $3.25 installed.
- Self adhering peel and stick, high temperature (under metal and tile): $1.20 to $2.50 material, $2.50 to $4.00 installed.
- Breathable membrane (unvented roof assembly): $0.80 to $2.00 material, $2.00 to $3.50 installed.
- Roofing felt, peel and stick hip and ridge, cap sheet: $0.50 to $1.50 per square foot material.
The installed numbers assume a clean deck and a crew already on the roof. Tear off, deck repair, and dry in work add $1 to $3 per square foot on top of these figures.
How to Calculate the Quantity You Need
Start with the roof square footage from your takeoff, pitch factor applied (a 6:12 pitch multiplies flat area by about 1.12). Convert to squares by dividing by 100. Add a waste factor of 10 percent for simple gable roofs and 12 to 15 percent for cut up roofs, because underlayment laps at every course and at every valley. Round up to the next full roll, because suppliers sell whole rolls and a partial roll order carries a cut fee.
Run the layers separately if the spec calls for more than one. A typical shingle roof spec is synthetic across the field, with self adhering membrane at the eaves (first 2 to 3 feet up from the edge), in the valleys, around penetrations, and at any ice dam prone detail. A metal or tile roof often specs self adhering high temperature across the whole field, not just the details. Count the lineal feet of eave, valley, hip, and ridge for the membrane runs and convert to rolls at 2 squares per roll.
Include fasteners or adhesive for the underlayment itself. Synthetic is usually capped with a few cap nails or staples to hold it down until the roof goes on; self adhering membrane needs a primer on some substrates, and primer is its own line. Drip edge, ice and water at rakes, and any high wind zone cap fastening go on the accessory list.
How to Buy Smarter
- Get three supplier quotes on every bid. Underlayment pricing swings 10 to 25 percent between distributors on the same type and thickness, often because of a regional stock or volume deal.
- Quote the type, mil thickness, temperature rating, and manufacturer by name. A "synthetic underlayment" quote is not comparable across suppliers unless the mil and the UV exposure rating match. 20 mil and 40 mil are not the same buy.
- Order in full roll multiples. Partial rolls carry a cut fee and a small order premium that wipes out your margin.
- Lock quotes for 30 to 60 days on longer bids. Asphalt and polymer pricing moves with petroleum, and a quote from last quarter is not your cost today.
- Bundle the underlayment with the shingle or metal order. You get better package pricing than buying the roof covering from one source and the underlayment from another, and one delivery is cheaper than two.
- Confirm the warranty tie. If the shingle or metal manufacturer requires their own underlayment for the system warranty, quote that brand or the warranty will not issue.
Where Estimators Get It Wrong
The biggest miss is quoting standard self adhering membrane under a metal or tile roof. The surface under metal and tile hits 250 degrees Fahrenheit and standard membrane melts, leaches adhesive, and eventually fails. High temperature membrane is required and runs 20 to 40 percent more. Quoting the wrong one is a callback and a warranty fight.
The second miss is undercounting the ice and water and detail membrane. A spec that calls for self adhering membrane at the eaves, in the valleys, around every penetration, and at any low slope section is buying membrane by the roll, not the square foot. If your bid only has field synthetic, you are underpriced at every valley and eave.
The third miss is the UV exposure rating on long jobs. Standard synthetic breaks down in 30 to 60 days of sun, and if the roof stays open longer, the crew has to strip and re lay it. High exposure membrane costs more up front and saves the re work. Match the rating to the schedule.
The fourth is the deck condition. Underlayment does not fix a bad deck. Rotted sheathing, skip sheathing gaps, and uneven boards all show through the membrane, and the manufacturer will not warranty the roof over a non approved substrate. Budget deck repair as a separate line, not an underlayment line.
The fifth is felt on a job that specs synthetic. Felt is cheap, but it tears when the crew walks on it, wrinkles when it gets wet, and will not support a modern shingle warranty. If the spec calls synthetic, do not price felt.
Putting It Together
For a bid, you want a field underlayment line priced per square (type, mil, and exposure named), a self adhering membrane line priced per square and per lineal foot of eave and valley, a high temperature membrane line if the roof is metal or tile, a primer and cap fastener line, a freight line, and a labor line. Roll them into an installed price per square foot for the owner, but keep them broken out in your backup so you can defend each number. Price the type, mil, temperature rating, and manufacturer by name, lock the quote for the bid window, and add a waste factor that matches the roof complexity. Do that and your underlayment bid will hold up when the quotes come back from the field.