How much does roof underlayment replacement cost?
How much does roof underlayment replacement cost?
$0.10 – $0.80 felt & tar paper materials cost per square foot
$0.75 – $4.00 cost per square foot installed
$1,100 – $9,000 average total cost to replace
Roof underlayment replacement cost
Roof underlayment replacement costs $0.75 to $4.00 per square foot or $1,100 to $9,000 on average, depending on the roof size, type, and if the underlayment is felt, tar paper, synthetic, or rubber. A roof underlayment’s lifespan is 20 to 30 years.
| Roof size (square feet) | Average cost to install |
|---|---|
| 1,000 | $750 – $4,000 |
| 1,500 | $1,100 – $6,000 |
| 2,000 | $1,500 – $8,000 |
| 2,500 | $1,900 – $10,000 |
| 3,000 | $2,300 – $12,000 |
| 3,500 | $2,600 – $14,000 |
*Cost data is from research and project costs reported by HomeGuide members.
Roofing felt & tar paper prices
Roofing felt material prices are $0.05 to $0.90 per square foot or $5 to $90 per 100 SF roll, depending on the type. Roofing felt, also known as tar paper, typically comes in 100, 200, or 1,000 square foot rolls.
| Material | Price per square foot | Compatible roofing systems |
|---|---|---|
| Asphalt felt | $0.05 – $0.15 | Asphalt shingles |
| Fiberglass felt | $0.15 – $0.70 | Asphalt shingles |
| Synthetic / Polypropylene | $0.10 – $0.35 | Metal, tile, wood, slate, asphalt shingles, flat |
| Rubber (SBS) | $0.20 – $0.90 | Metal, tile, wood, slate, asphalt shingles, flat |
*Not including labor
Roofing felt prices depend on:
Type – Synthetic (plastic) and rubberized asphalt (SBS) are lighter, easier to install, and more expensive than traditional asphalt-saturated felt.
Fire rating – All underlayments are fire-resistant, but the quality varies. Select underlayment with a Class A rating for maximum fire resistance.
Roll width and length – Underlayment rolls vary in size, from 3x33, 3x66, to 4x250 feet.
Thickness – Rubber or synthetic underlayment is thinner but more expensive and durable than felt.
Brand – The most popular and trusted underlayment brands include GAF, Owens, GCP, Tyvek, Grace, Epilay, APOC, and CertainTeed.
Features – Asphalt roofing felt is water, mildew, and corrosion-resistant. Synthetic and rubberized underlayment is waterproof, high-wind resistant, and more durable in extreme heat and cold.
Difference between 15 and 30-pound roofing felt
Asphalt felt comes in rolls that weigh 15 or 30 pounds per 100 square feet. 15-pound felt is thinner and more flexible, while 30-pound felt is more water-resistant, expensive, and less likely to tear. A flat or low-slope roof typically requires thicker felt than a steep roof.
Cost factors to replace roof underlayment
Labor to replace roofing felt costs $0.65 to $3.20 per square foot. Most contractors install new underlayment when replacing the roof and factor the cost into the installation estimate.
| Factor | Cost per square foot |
|---|---|
| Roofing felt / tar paper materials | $0.10 – $0.80 |
| Installation labor | $0.65 – $3.20 |
| Total cost to replace | $0.75 – $4.00 |
The following factors affect the cost to replace:
Roof size, slope, complexity – A large, low-sloped, or complex roof needs more underlayment than a small, simple roof.
Labor – Costs increase for homes with multiple stories, high roofs, or steep roofs.
Material type – Synthetic and rubberized underlayments are more expensive than fiberglass and asphalt felt, especially when self-adhesive.
Application method – Felt underlayments are typically nailed on. Synthetic and rubber sheets often have peel & stick or self-adhered backing, which is more expensive but more weatherproof.
Roof penetrations, pipe boots / ridge ventilation – Installing a roof vent costs $200 to $700.Existing penetrations take time to work around and may increase labor costs.
Plywood sheathing – Replacing roof decking costs $2 to $5 per square foot. If the decking is damaged or corroded, it may need to be replaced before new felt is installed.
Roof repairs – Roof repairs cost $150 to $6,000 on average, depending on the type and extent of the damage.
Warranty – Many underlayment manufacturers offer 10 to 30-year warranties, but underlayment is often covered by roofing warranties instead.
Permit – A roofing permit costs $150 to $500 for replacement and $70 to $250 for repairs. Contractors typically include the cost of a roof permit in the estimate.
Felt and tar paper underlayment FAQs
What is roof underlayment?
Roof underlayment is a layer of insulation between the roofing material and decking. Underlayment increases the roof’s lifespan and protects against severe weather, mildew, wood rot, and mold.
Asphalt-saturated felt, also known as tar paper or felt paper, is made from wood pulp or polyester coated or soaked in asphalt. Other types are made with rubberized asphalt, fiberglass mats, and polypropylene plastic. Underlayment is not toxic but may release harmful fumes if heated or on fire.
How long does roof underlayment last?
Asphalt felt underlayment lasts 20 to 30 years, while synthetic or rubberized underlayment lasts 25 to 30 years. Inspecting underlayment every 3 to 5 years may increase its lifespan. Extreme heat or cold, storm damage, or pests may reduce its lifespan.
Tip: Underlayment may need to be replaced soon if it is brittle, curling, or shrinking.
What is the best roofing underlayment?
The best roofing underlayment depends on the roof material, pitch, and climate. Asphalt felt is best for asphalt shingles and mild climates. Synthetic or rubberized felt is waterproof and more resistant to UV, high winds, tearing, ice, and extreme heat.
Is roofing felt waterproof?
Asphalt roofing felt is water-resistant but not fully waterproof. Rubberized felt and synthetic underlayment are waterproof.
How long can roofing felt stay exposed?
Asphalt felt may tear or wrinkle if exposed for more than a few hours. Synthetic or rubberized underlayment can stay exposed to sun or moisture for several weeks.
What roof types need tar paper underlayment?
Almost all roof types require at least one layer of underlayment. A metal, slate, or wood roof performs better with synthetic or rubberized underlayment. Asphalt shingles do well with 15- or 30-pound asphalt felt.
How many layers of felt go under a roof?
At least one layer of felt goes under a roof, depending on the roof type and slope. A flat roof or a roof with a slope under 4:12 typically needs two layers.
How many square feet in a roll of roofing felt?
Roofing felt comes in rolls of 100, 200, or 1,000 square feet.
Getting estimates from roofing contractors
Before hiring a roofing contractor near you, be sure to:
Get three or more quotes to compare.
Read their reviews on HomeGuide and Google.
Look for companies with a state contractor license, a National Roofing Contractors Association (NRCA) certification, and an International Association of Certified Home Inspectors (InterNACHI) certification.
Select a certified, insured, bonded company with five or more years’ experience.
Be careful with extremely low or high price quotes.
Beware of companies who recommend a full roof replacement if only repairs are needed.
Verify that the roofing contractor has experience with your roof type.
Ask for a clear written estimate and warranty before work begins.
Avoid large upfront payments. Instead, negotiate a payment schedule and save receipts.
Questions to ask
How long have you been in business?
Are you licensed, insured, and bonded?
Can you provide references for past work?
Are you a member of the NRCA or InterNACHI? What certifications do you have?
Can you provide a detailed quote?
Does your quote include waste disposal or taxes?
How long will the project take?
Which type of underlayment do you recommend for my roof’?
What will you do in the event of unexpected bad weather?
How will you access my roof? What safety precautions will you take?
What additional costs should I expect?
Will you obtain any necessary permits?
What does your warranty include?
Do you offer financing?