Roof underlayment replacement costs $3,300 on average, and most homeowners pay between $1,700 and $4,200, depending on the type of underlayment, roof's size, and pitch.
Roof underlayment replacement costs around $3,300 on average, but your total could fall anywhere between $300 and $8,200, depending on roof size and pitch, the type of underlayment you install, and some other factors.
In this guide, we’ll explain the factors that affect the cost to replace roof underlayment to help you get a more accurate estimate for your roof replacement project.
The size of your roof will be the most significant factor when determining the total cost of roof underlayment replacement, as many roofers will charge by the square foot. Larger roofs require more underlayment material and require more time and effort to carry out the installation. Replacing roof underlayment costs an average of around $1.60 per square foot, with prices ranging from $0.60 to $2.70 in most cases.
You can get a more accurate estimate if you calculate your roof’s square footage and then multiply by these average prices.
| Roof Size in Square Feet | Roof Size in Squares | Price Range |
|---|---|---|
| 500 | 5 | $300–$1,350 |
| 1,000 | 10 | $600–$2,700 |
| 2,000 | 20 | $1,200–$5,400 |
| 2,500 | 25 | $1,500–$6,800 |
| 3,000 | 30 | $1,800–$8,200 |
Roof underlayment material is quite affordable, so the majority of your money will go toward labor, usually accounting for between 80% and 90% of the total. Labor will typically cost between $1,400 and $3,800 for roof underlayment replacement, with an average of around $2,800.
Roof underlayment replacement can vary by location, too, with prices sitting higher in states with a higher cost of living, as well as more expensive areas like major cities.
| State | Underlayment Cost |
|---|---|
| California | $4,800 |
| Florida | $3,400 |
| Georgia | $3,000 |
| Illinois | $3,100 |
| Michigan | $3,000 |
| New York | $4,100 |
| North Carolina | $3,300 |
| Ohio | $3,100 |
| Pennsylvania | $3,200 |
| Texas | $3,000 |
Location can also play a role in roof underlayment replacement costs because certain climates and weather conditions can dictate what type of roof underlayment is best for safety and efficiency or what’s best for the particular type of roof that’s most common in your area. For example, metal roofs are more common in areas where homes have steep roofs to shed heavy snowfall, and the best underlayment for a metal roof can be more expensive than what would be appropriate under an asphalt shingle roof.
There are some other important factors to consider if you want the most accurate estimate possible for your roof underlayment replacement project.
Your roof pitch will play a role in your total in a few ways. First, steeper roofs have larger surface areas that require additional materials and labor to get the job done, so a steep roof on a 1,000-square-foot home will cost you more in underlayment replacement costs than a shallow roof on a similarly sized property due to the difference in surface area.
Steep roofs are also more challenging and dangerous to work on, so roofers may bump up labor costs if they need additional safety equipment to get the job done.
Finally, roof pitch influences what roofing materials are suitable for your home, and the roofing material, in turn, affects the best type of roof underlayment. The indirect relationship between roof pitch and underlayment material can cause your price to increase or decrease based on the material cost of the underlayment you need.
There are three main types of roof underlayment, and each comes at a different price per square foot. Rubber underlayment is the most expensive but is the only true waterproof underlayment. You’ll often find it on flat roofs or low-slope roofs rather than under asphalt shingles or other roofing materials. Roof felt is the most common and most affordable underlayment, and it’s considered the best roof underlayment for asphalt shingles.
| Underlayment Type | Average Material-Only Price Per Square |
|---|---|
| Felt | $5–$55 |
| Synthetic | $18–$60 |
| Rubber | $50–$75 |
In preparation for underlayment installation, your roofer will need to remove your old roof and old underlayment, and you’ll pay between $1,000 and $5,000 for the removal.
They will install underlayment under your new roof material but over the roof decking or sheathing below. If you find damage to your roof decking when you remove your old roof, you might need to pay extra for roof decking repairs. New roof sheathing costs between $2 and $5 per square foot for materials and labor.
In most municipalities, you’ll need a building permit before you can legally replace your roof. There’s no permit specifically for roof underlayment replacement, but you will need one to install new roofing over the underlayment. The permit cost for a full roof replacement, including replacing the underlayment, is usually between $100 and $500.
Installing roof underlayment yourself will save you quite a lot of money, as most of the cost goes toward labor. For the typical roof size, you can expect to save between $1,700 and $4,200 by doing the work yourself.
A DIY roof underlayment replacement is generally less risky than installing the actual roofing material yourself because the underlayment acts as a second layer of defense against water intrusion. However, working on a roof is dangerous, and the process needs to be precise to limit the risk of roof leaks.
It’s a better idea to leave the work to the local roofing company that’s also installing your roofing material. This reduces the risk of expensive property damage, and you won’t have to coordinate as closely with your pro to time removing your old roof and installing the underlayment right before they arrive to install the roof above. Some types of roof underlayment can stay exposed for months with minimal risk, but it’s still better to have your roofer carry out everything at once.
Roof underlayment replacement costs an average of $3,300, while repair is much more affordable and usually included in a total roof patch or leak repair. These services cost between $500 and $1,000, in most cases, with only a small fraction of that going toward underlayment repair.
Unless you’re dealing with a small leak and you know the rest of your roof has a lot of useful life left in it, it’s usually better to replace the underlayment and the roofing material above for the longest-lasting solution.
Roof underlayment replacement costs can climb up to around $8,200, but there are some things you can do to help keep costs down.
Choose the right material for your home. The three types of roof underlayment come with different material costs. You can save a few hundred dollars by choosing felt over synthetic or rubber underlayment, provided it’s a suitable option for your climate.
Repair over replace when possible. If you just have a small leak, you can save thousands by having a professional patch it rather than replace the entire roof. Have a roof inspection done, or ask a pro beforehand if a patch would be a good option.
Hire a professional. Hiring a professional to install new roof underlayment will cost you significantly more than if you DIYed the work, but proper installation could save you even more money over time by avoiding property damage and expensive roof leaks.
Replacing your roof underlayment won’t add much, if anything, to your home value, but replacing an old roof along with the underlayment almost always will. Most homeowners see an ROI of between 60% and 70% on roof replacement because the project improves curb appeal, secures a lengthy warranty for the roof, and provides peace of mind for buyers who may otherwise worry about having to pay to replace the roof after closing.
Home is the most important place on earth, which is why Angi has helped more than 150 million homeowners transform their houses into homes they adore. To help homeowners with their next project, Angi provides readers with the most accurate cost data and upholds strict editorial standards. We extensively research project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We rely on reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects.
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Roof underlayment usually lasts as long as the roofing material that covers it, as it’s not directly exposed to the elements. Generally, roofing companies will replace the underlayment each time they install a new roof. In some cases, particularly with slate, clay, or certain metal roofs that can last 50 to 100 years, your underlayment may require replacement within that timeframe, especially if you start to notice roof leaks.
You shouldn’t put a new roof underlayment over an old one for a few reasons. Mainly, old felt must be removed in order to assess the condition of your roof decking, such as rotting wood or other structural issues. Also, if your roofer doesn't install a fresh layer of felt as is required by shingle manufacturers, it may void your warranty. Finally, old underlayment removal is often included in the cost of roof repair or replacement, so there's no real benefit to leaving it on before installing a new layer.
