Whether you’re building a home or embarking on a reroofing project, there are several factors to consider when choosing which underlayment type to use.
Thanks to its many advantages, synthetic roof underlayment is taking over the roofing industry.
Synthetic underlayment is sturdy and dependable and will outlast most traditionally used underlayment types.
To start working on your roofing needs, contact your local roofing pros for FREE ESTIMATES!
Can I Use Synthetic Roofing Underlayment?
You can use synthetic roof underlayment provided you purchase the right type for your roofing material, and your local building code allows its use.
Synthetic Roof Underlayment Average Cost
On average, homeowners pay approximately $1,400 to install synthetic roof underlayment on a 2,000-square-foot roof.
The total cost includes the price of materials and the labor cost.
Certain factors can contribute to a higher installation cost, including the following:
- Warranty. Certain products come with specific installation requirements to avoid a breach of warranty. These might include special fasteners that will increase the project’s total cost.
- Code. Some areas in the U.S. require placing two layers of underlayment to protect the roof.
- Roof pitch. The steeper the pitch, the higher the installation costs.
Synthetic Roof Underlayment Cost Breakdown
Synthetic roof underlayment materials cost between $0.15 and $0.65 per square foot.
The higher the price, the more durable and long-lasting the synthetics.
Generally speaking, synthetic underlayment products can be broken down into three categories:
- 25-year non-adhesive underlayment: starting at $0.15 per square foot
- 50-year non-adhesive underlayment: starting at $0.20 per square foot
- 50-year self-adhesive underlayment: starting at $0.55 per square foot
| Synthetic Underlayment Type | Average Material Cost per Square Foot | Average Labor Cost per Square Foot | Average Total Cost for a 2,000-Square-Foot Roof |
|---|---|---|---|
| 25-Year Non-Adhesive Underlayment | $0.15-$0.20 | $0.15-$0.50 | $600-$1,300 |
| 50-Year Non-Adhesive Underlayment | $0.20-$0.25 | $0.15-$0.50 | $700-$1,500 |
| 50-Year Self-Adhesive Underlayment | $0.55-$0.65 | $0.15-$0.50 | $1,400-$2,300 |
See costs in your area
Start Here - Enter Your Zip Code
Who Makes Synthetic Roof Underlayment?
As synthetic roof underlayment increases in popularity, so will the number of brands that produce this building material.
Here are some of the stand-out brands.
Sharkskin
The Sharkskin underlayment products are manufactured by Kirsch Building Products.
The brand offers a premium product line made by a roofer for roofers.
The entire line is recyclable, made in the U.S., and contains no VOCs (volatile organic compounds).
The brand offers three types of synthetic underlayment products.
- Sharkskin Comp, an entry-level synthetic underlayment ideal for metal and shingle roofing. It can be exposed for up to six months and lasts up to 30 years. Sharkskin Comp costs around $0.20 per square foot.
- Sharkskin Ultra, a heavier and more durable option that is perfect for shingles, tile, metal, and slate roofing systems. It can be exposed for up to 12 months and last up to 50 years. Sharkskin Ultra costs approximately $0.25 per square foot.
- Sharkskin Ultra SA, a state-of-the-art synthetic underlayment suitable for all roofing types. It works well in areas with extreme weather conditions. This underlayment product can be exposed for up to 12 months and lasts up to 50 years. Sharkskin Ultra SA costs around $0.50 per square foot.
InterWrap
InterWrap is a global manufacturer of various roofing products, including synthetic underlayment.
The company operates facilities in Canada, the U.S., India, and China.
InterWrap’s star product, the Original RhinoRoof U20 underlayment, costs approximately $0.25 per square foot.
FT Synthetics
FT Synthetics is a worldwide manufacturer of synthetic roofing underlayment and related construction products.
The company focuses on research and development, allowing it to produce high-quality and safe underlayment products.
FT Synthetics manufactures products in two locations, one in Canada and the other in China.
FT Synthetics’ top synthetic roof underlayment product is HYDRA and it costs around $0.25 per square foot.
Cost per sq. ft.
Roof Size:
Roofing Material:
See costs in your area
Start Here - Enter Your Zip Code
Who Sells Synthetic Roof Underlayment?
Most metal roof suppliers offer synthetic underlayment products.
The list of sellers also includes some big box stores, such as Home Depot and Lowe’s.
Pro Tip: If you work with a roofing contractor, they will provide all the necessary installation accessories, including the underlayment material. The added bonus is that the material will often be cheaper this way since most manufacturers offer discounts on bulk purchases. As an individual, you’re unlikely to get a better deal on the underlayment rolls, but your contractor will probably have no issue buying the material for less.
Synthetic Roof Underlayment Home Depot
Home Depot offers a decent selection of roof underlayment products, including synthetic underlayment.
On average, synthetic underlayment costs around $0.50 per square foot.
If you’re shopping online, you can use the handy filters to purchase products based on the compatible roofing system, application method, and additional features.
Home Depot offers one of the best underlayment products on the market. This product is GAF FeltBuster Synthetic Roofing Felt.
GAF FeltBuster Synthetic Roofing Felt is exceptionally lightweight and easy to install, Class A fire resistant, and has a nailing pattern on the front. It’s sold as a 1,000-square-foot roll that costs $98.98.
Synthetic Underlayment Weight vs Mil Thickness
The synthetic underlayment weight is the best indicator of its quality.
A higher weight usually points to a membrane layer responsible for the material’s waterproofing and abrasion resistance properties.
Some synthetic underlayment products are marketed as having a higher mil thickness. However, this shouldn’t be confused with the overall thickness of the material.
Instead, a higher mil thickness typically indicates the presence of a fuzzy top layer whose primary purpose is to improve walkability. As such, it contributes to the overall quality of the product significantly less than its weight.
How To Install Synthetic Roof Underlayment
Synthetic underlayment is easier to install than other underlayment options for several reasons.
Firstly, the synthetic underlayment rolls are more lightweight, which makes them easier to carry and move around the roof.
Secondly, the material isn’t slippery, making it safer to walk on.
And finally, synthetic underlayment is made from laminated polypropylene or polyethylene plastic, which is exceptionally resistant to tearing. As a result, it won’t break or tear as the screws and nails penetrate it.
Thanks to these properties, most DIY-savvy homeowners can install synthetic underlayment independently, provided they own the necessary tools.
These tools include:
- A roofing hammer
- A utility knife
- Roofing nails
- A pair of roofing gloves
Pro Tip: Be mindful of the nails you use, especially if installing synthetic underlayment on a metal roof. If you use nails made from a dissimilar metal, you risk corrosion and lessening the roofing system’s longevity. For instance, electro-galvanized (EG) nails should never be used on aluminum or copper roofs.
When installing synthetic roof underlayment, homeowners should keep several things in mind.
- Fastening the product with capped nails instead of staples is crucial, especially if the underlayment will stay exposed for some time.
- The compatibility between the synthetic underlayment and the roof type is instrumental since not all roof types can be installed over all types of synthetic underlayment.
- The synthetic underlayment should be used in conjunction with a peel-and-stick underlayment. The latter should cover wall intersections, valleys, and overhangs.
See costs in your area
Start Here - Enter Your Zip Code
Benefits Of Synthetic Roof Underlayment
Synthetic roof underlayment has plenty of benefits that make it the best roof underlayment option on the market.
Synthetic Roof Underlayment Is Highly Resistant to Mold and Mildew
Synthetic underlayment provides a superior moisture barrier, preventing water from easily entering a home.
This attribute especially comes in handy during storms since most roof underlayment types absorb the rainwater, get soggy, and eventually become moldy.
In contrast, synthetic underlayment can weather the storm and significantly reduce the chances of rainwater penetrating the decking. This prevents the decking from being perpetually moist, which is a breeding ground for mold and mildew.
Synthetic Roof Underlayment Can Remain Exposed Longer
Synthetic underlayment is designed to withstand extreme weather conditions that would otherwise wreak havoc on the house.
Since it doesn’t absorb moisture, the elements won’t damage the material for months, despite direct exposure.
In some cases, synthetic underlayment can remain exposed to adverse weather conditions for up to 30 months and remain watertight.
Synthetic Roof Underlayment Lasts Longer
Besides being resistant to moisture and the elements, synthetic underlayment is highly resistant to rips and tears.
It’s unlikely to get damaged or fall apart even when directly hit by items such as small tree limbs. This sturdy material is built to withstand the test of time, which it successfully does, as it can last up to 50 years.
Synthetic Roof Underlayment Is Safer for Walking
Safe working conditions are essential in any situation, but they become paramount for steep roofs.
Unlike traditional underlayment options, synthetic underlayment isn’t slippery.
In fact, the synthetic underlayment provides superior traction, thus limiting dangerous slips and falls.
As a result, synthetic underlayment is much easier and safer to work with and walk on.
Synthetic Roof Underlayment Is Lighter and Easier to Install
Besides providing excellent traction for roofers, synthetic underlayment is more lightweight than traditional underlayment options, making it even easier to carry and install.
Plus, this material comes in longer and broader rolls, resulting in fewer trips up and down the ladder.
Did you know? An average 2,000-square-foot house would require up to 13 rolls of traditional felt underlayment. In contrast, less than three rolls of synthetic underlayment would suffice to get the job done.
Cost per sq. ft.
Roof Size:
Roofing Material:
See costs in your area
Start Here - Enter Your Zip Code
Problems With Synthetic Roof Underlayment
While synthetic roof underlayment offers plenty of benefits compared to traditional underlayment materials, homeowners should keep a few issues in mind.
Synthetic Roof Underlayment Is More Expensive
The cost of the synthetic underlayment is its most significant disadvantage.
It can cost twice as much as traditional felt underlayment.
However, this only pertains to the upfront investment. While synthetic underlayment is costlier to install, it will save homeowners money down the road thanks to its durability and superior protection.
Not All Synthetic Roof Underlayment Is Created Equal
Unfortunately, some synthetic underlayment brands manufacture subpar products. They typically brand their materials as having increased mil thickness.
However, mil thickness usually entails an added layer for walkability, which doesn’t increase the overall thickness of the material.
Some Building Codes Prohibit Synthetic Roof Underlayment
Before installing synthetic underlayment, homeowners should consult their roofing contractors to ensure this material is up to code in their area.
Although rare, synthetic underlayment will be prohibited under specific circumstances, forcing homeowners to install felt underlayment.
Synthetic Roof Underlayment vs Ice And Water Shield
The peel-and-stick underlayment is often referred to as an ice and water shield.
An ice and water shield is an excellent underlayment choice for low-slope roofs and houses in climates experiencing heavy rain, snow, and high winds. Areas with these weather conditions often require the installation of an ice and water shield.
An ice and water shield is exceptionally durable.
The ice and water shield minimizes the risk of water penetration, thus protecting the roofing system from damage.
It’s primarily recommended for roof areas with the greatest risk of ice damage, such as eaves, valleys, and ridges.
The best practice is combining this flexible underlayment with another underlayment layer, such as synthetic underlayment.
Although an ice and water shield isn’t as crucial as synthetic underlayment, it can make a world of difference in protecting the roof from damage caused by ice dams.
See costs in your area
Start Here - Enter Your Zip Code
Synthetic Roof Underlayment vs Felt
Like synthetic underlayment, roofing felt is a layer that acts as a barrier between the roof decking and the elements.
Felt is usually manufactured using natural materials such as wood cellulose.
A felt underlayment comes in two weights, 15 and 30 pounds. The latter provides better protection since it’s thicker and more resistant to damage.
Felt has been the most popular roof underlayment material for decades. However, this might change in the coming years, thanks to the superiority of synthetic underlayment.
With this in mind, let’s see how these two materials compare.
Did you know? The use of roofing felt dates back to the California Gold Rush and the middle of the 19th century. During this frenzy, thousands of hopeful prospectors, nicknamed forty-niners, poured into the state. They used roofing felt to cover the roofs of their temporary shacks. The material eventually came to be used as an underlayment as well.
Synthetic Underlayment Comes in Larger Rolls
Synthetic underlayment rolls are longer and cover more square footage than their felt competitors.
So, roofers need to make fewer trips to fetch products, resulting in faster project completion.
Synthetic Underlayment Rolls Are Lighter
Getting roofing materials on the roof can be highly challenging. Naturally, the lighter the material, the easier it is to carry up the ladder.
Synthetic underlayment rolls are lighter and provide more square foot coverage, making them easier to carry and work with.
Synthetic Underlayment Resists High Winds
The synthetic underlayment will stay in place during high winds when appropriately fastened.
In contrast, high winds usually lead to chasing airborne felt underlayment around the neighborhood or pulling it out of the surrounding trees.
Synthetic Underlayment Captures Less Heat
Darker roofing materials absorb significantly more heat than their lighter counterparts. The heat can cause a lot of damage to the roof in the long run.
Since roofing felt is typically black, it creates a much hotter roofing surface in the sun.
Synthetic Underlayment Is Safer
Felt underlayment has a slippery surface that can create more dangerous working conditions for roofers.
In contrast, synthetic underlayment gets tacky when wet, providing traction and significantly improving walkability for roofing contractors.
Synthetic Underlayment Lasts Longer
The average life expectancy for felt underlayment is between 10 and 20 years.
This is about half that of a synthetic underlayment, which is expected to last between 25 and 50 years.
Pro Tip: Despite its increased durability, it’s prudent to have synthetic underlayment inspected as frequently as felt underlayment. These inspections should be conducted every three to five years or sooner if a problem arises.
Synthetic Underlayment Is More Expensive
Cost is the only aspect where felt has the upper hand compared to synthetics.
Namely, felt underlayment is up to two times less expensive than synthetic underlayment.
With synthetic underlayment, the high price comes from the material’s weight. The heavier the synthetic underlayment, the more walkable and durable it is and the more expensive.
Synthetic Roof Underlayment vs Peel And Stick
A peel-and-stick underlayment is also called an ice and water shield.
This underlayment type is often combined with synthetic underlayment because it provides superior protection against ice dams.
In addition, the peel-and-stick underlayment:
- Is easy to install since it doesn’t require any nailing
- Provides an excellent barrier, minimizing the risk of water penetration
- Is more flexible and durable than traditional underlayment solutions
House Wrap vs Synthetic Roof Underlayment
A house wrap is a synthetic material that functions as a barrier, preventing rain from penetrating the walls and protecting the building against the elements.
For this reason, a house wrap also improves the building’s energy efficiency.
In this sense, a house wrap is similar to synthetic roof underlayment, as they both serve the same purpose.
However, unlike synthetic underlayment, a house wrap is breathable. This characteristic permits water vapor transfer from inside the building. If vapor was allowed to build up within the walls, it would decrease the insulation properties.
Since synthetic underlayment isn’t breathable, homeowners should never use it as a house wrap for siding.
Cost per sq. ft.
Roof Size:
Roofing Material:
See costs in your area
Start Here - Enter Your Zip Code
What Is The Best Roofing Underlayment?
Synthetic underlayment is by far the best roofing underlayment choice.
It’s substantially more moisture- and damage-resistant, sturdier, and more durable than other underlayment types.
What Is The Best Synthetic Roofing Underlayment?
The best synthetic roofing underlayment matches the roof’s lifespan.
For instance, homeowners with metal roofs designed to last over 50 years should purchase a synthetic underlayment product with the same expected lifespan and warranty.
How Long Can Synthetic Underlayment Be Exposed?
Unlike traditional underlayment options, synthetic underlayment can be exposed for several months without worrying about damage.
Moreover, some quality materials can be exposed for up to 30 months and remain intact.
This impressive characteristic makes synthetic underlayment ideal for projects that can’t be completed immediately.
Can Synthetic Roof Underlayment Get Wet?
Synthetic roof underlayment can get wet.
In fact, it can stay wet for extended periods thanks to its superior moisture resistance.
Is Synthetic Roof Underlayment Breathable?
Synthetic roof underlayment is not breathable.
This product has a low perm rating, meaning it stops water vapor movement. As a result, proper attic ventilation is crucial for homes with synthetic roof underlayment.
Investing In The Future
Compared to other traditional options, synthetic roof underlayment is a superior product through and through.
It lasts longer, offers a smoother appearance, better mold and mildew resistance, and is easier and safer to install.
It might also be costlier to install, but it offers significantly better protection to probably the most expensive investment you own: your home.
Plus, it’s only a matter of time before the prices drop, which will undoubtedly cement synthetics as the only way to go regarding roof underlayment.
See costs in your area
Start Here - Enter Your Zip Code
For over 20 years Leo has run a successful roofing business in New England, specializing in metal roofing, as well as cool flat roofing technologies. Having replaced and installed hundreds of roofs in New England, Leo has first hand experience with pretty much every residential roofing material and roofing manufacturer available in the US.
Since my house has no roof ventilation on the north side and i have high rise ceiling (living room area), I have no choice to go back to the felt paper (this time 2 layer of 30lb each). For my South and West side, there are attics but I only have eave ventilations and 1 attic ventilation, I consider putting 3 roof ventilations. My question is can I do 1/2 synthetic (on South and West side) and 1/2 2 layers felt papers (on the North side)? Or do I have to do the whole cement tile roof with 2 layers of felt papers (30lb each)?
Another question is should I also have the “peel & stick layer” before 2 felts layers, is this “peel & stick layer” is breathable? If not, it may cause mold on the inner side of the felt papers?
Thanks & God bless,
Hai
Hai, you could do half and half, but really the cost of synthetic will maybe add $100 total in materials, and should NOT increase installation cost AT ALL.
A 1000 s.f. roll of GAF DeckArmor is like $220-250 (home depot has it for $249, and roofing suppliers may offer better deal).
#30 felt is $35 for 216 s.f. roll, so to get same coverage as 1 roll of deck armor, you need 5 rolls of felt, which is $175. That is only $75 difference.
Benefits of deck armor: besides being breathable, it is SUPER strong, and super water prof. We were doing a restaurant roof in Boston one time … it was the 2009 SNOWMOGEDDON , and it was snowing almost every day for like 3 months. So the roof was basically covered with DeckArmor for 4 months, and not a single leak.
Also, when your shingles will be at the end of life, and with no ventilation, I would say you will get 10-15 years… So by then, felt will be brittle junk, while DeckArmor should give you extra 5+ years of no leaks!
One important thing – tell your roofer NOT TO USE STAPLES. Only plastic cap nails when installing Deck Armor!
Good luck