Knowing your home's roof underlayment replacement cost can help estimate the cost of roof replacement. Learn about the factors that affect prices.
How Long Can Roof Underlayment Be Exposed?
Don’t underestimate the importance of underlayment
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Roof underlayment water resistance depends on the type you have: synthetic underlayment is waterproof and can stay exposed for up to six months.
Expect to pay $3,100 on average for complete underlayment replacement, with costs ranging from $3 to $5 per square foot depending on your roof size.
Felt underlayment breaks down quickly when exposed to sun and moisture, so you should prioritize replacing it immediately to avoid further roof damage.
Hiring a local roofing professional provides reliable support for underlayment replacement and shingle repairs, keeping your home protected from water damage and the elements.
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When it comes to roof underlayment, it’s out of sight out of mind for most homeowners. Sandwiched in between roofing layers, this protective element does its job best when unseen.
However, if storms or heavy winds damage the roofing above it, the underlayment can be exposed. So, what happens when this unsung hero of the roof is revealed? And how long can roof underlayment be exposed before it’s damaged? We’ll explain everything you need to know.
What Is Roof Underlayment?
Roof underlayment is one of the many protective layers of roofing that keep a home safe from the elements. The uppermost layer of roofing is the shingles or another external roofing material, followed by the underlayment, sheathing, and finally, the rafters.
Underlayment is constructed from waterproof and durable materials as an added layer to keep moisture out of a home beyond just the shingles. Underlayment helps prevent mold, damage, and moisture from entering a home.
Types of Roof Underlayment
Homes have one of three types of roof underlayment under their roofing—either felt, synthetic, or rubberized asphalt underlayment.
| Underlayment Type | Life Span (Years) | Benefit | Drawback |
|---|---|---|---|
| Felt | 10–25 | Affordable | Water-resistant, not waterproof |
| Synthetic | 25–35 | Durable | May trap moisture |
| Rubberized Asphalt | 25–35 | Easy to patch | Expensive |
Felt Underlayment
Felt underlayment, also called roofing felt or felt paper, is the oldest and most commonly used type of underlayment material. It’s made using paper or felt saturated in tar to make the material water-resistant.
Felt underlayment is often the most affordable option and comes in various thicknesses. However, the felt underlayment is only water-resistant and not waterproof.
Synthetic Underlayment
Compared to felt underlayment, synthetic underlayment is more durable and lasts longer. It's made of woven synthetic polymers like polypropylene and polyethylene. In addition to its durability, it is also heat-resistant, making it the best underlayment for a metal roof.
While synthetic underlayment is lightweight and long-lasting, it can potentially trap moisture build-up between the sheathing and underlayment, impacting the roof's longevity.
Rubberized Asphalt Underlayment
Also called self-adhered underlayment, rubberized asphalt is the only truly waterproof form of underlayment. This underlayment is made of rubber polymers and asphalt with a sticky back, making installation easier than other underlayments.
While rubberized asphalt is easy to install and waterproof, it’s also the most expensive option.
How Long Can Roof Underlayment Be Exposed?
How long roof underlayment can be exposed to the elements depends on a few factors, including type of underlayment, environment, and condition.
Synthetic and asphalt underlayment can be exposed to the elements for the longest, up to six months, depending on its age. The underlayment can break down faster in sunny climates or particularly wet or moist environments.
On the other hand, felt underlayment can break down quickly when exposed to the sun and moisture. Ideally, roofing should be installed on the same day as felt underlayment. If felt underlayment is exposed, homeowners should prioritize replacing it quickly to avoid further damage to the roof.
Repairing Roof Underlayment
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If a storm, heavy winds, or debris exposes roof underlayment, it’s important to repair the damage as quickly as possible to avoid additional damage. We recommend choosing a trusted roofer to replace shingles instead of DIY-ing if the underlayment is in good condition.
However, if the underlayment was exposed during a downpour or has been left exposed for an extended period, you’ll likely need to replace a portion or all of a roof’s underlayment.
Completely replacing roof underlayment costs $3,100 on average but can vary based on the roof size and materials. Replacing underlayment costs between $3 and $5 per square foot.
Once you notice any exposed underlayment, reach out to a professional roofer near you to begin repairs as soon as possible.
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Roofing services reviews from real Angi homeowners in Columbus, OH
4.3★ avg. • 121 total reviews
- Carla M.
Mitchell and the crew were top tier i am so happy with my new roof
Home Genius Exteriors - Chance R.
D1 Roofing delivers outstanding service from beginning to end, backed by a strong warranty and expert teams. I highly recommend them for their excellence in meeting and surpassing expectations with unmatched communication. Choosing D1 Roofing was flawless decision
Division 1 Roofing LLC - Jeremy P.
This place took $25,000 for a flat roof job with a five-year warranty and never returned to fix the leaks that were caused by their work. These people are not professionals and should not be doing this type of work. They incorrectly changed the pitch of the roof, and caused more damage than...
- David B.
The technician was very professional and friendly. He answered all my questions and was very thorough. He left the fireplace area very clean . He inspected from the roof and advised me as to other work that might need to be done. There was no pressure there. I was very satisfied with the...
Supreme brick & chimney - Kevin S.
I am really impressed with their timeliness and turnaround. Mitchell came out, and we decided to move forward with their pricing. Our roof was on within a week, and we could not be happier with their team! Amazing company, great prices and honest, dependable craftsmanship. I highly recommend...
Window Depot USA of Central Ohio - Rob B.
Manuel Calvillo is the best option in the area for roofing and you won't be disappointed.
- Julie K.
They damaged multiple items on my property, including a marble slab used as a table top, tried to hide it, and refused to pay or replace. Arrived day one without a ladder to access roof & delayed a day. Left a mess in back yard; didn't wear face masks; no show by owner to property to see damages
Grants Tree Service - Marcia L.
I've hired Gary/Cherokee Roofing for two different homes, work quality, responsiveness, and completion have been great both times. And the prices quoted were very competitive. I would definitely hire again.
- Paul F.
Lyle did a great job removing asbestos shingles from our front porch roof. They worked together with our roofer to make sure that the new roof was able to be installed on the same day that Lyle removed the asbestos shingles.
Lyle Environmental - Paul F.
Bradley Builders did a good job replacing the roof on our front porch. They color-matched the existing shingles on the rest of the house and installed a metal ridge roll since we live in a historical neighborhood. They did the job while we were out of town. When we got back, everything was...
Bradley Builders, Inc.
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