What’s the better choice for your roofing projects—traditional asphalt felt underlayment or modern synthetic underlayment? There are a lot of considerations to make, and the cost is a big one. It may seem like in an even cost comparison, felt wins out over synthetic underlayment—but you may actually discover that in terms of cost-effectiveness, synthetics are truly the better choice.
That’s why, in this blog, we’re going to discuss some of the advantages and cost savings that come with using synthetic roofing underlayment.
How Does Synthetic Underlayment Compare to Felt?
All types of roofing underlayment are meant to act as an extra layer of protection between the primary roofing material and the roof deck beneath. Their main purpose is to protect the roof deck against moisture damage, be it from moisture that seeps between shingles, or the kind of damage that can happen when high winds tear off shingles or other roofing materials.
In general, synthetic underlayment does a better job at this than roofing felt—and that’s because even though most synthetics are lighter weight than asphalt felt, they’re much more durable. Where felt is basically paper coated in tar, synthetic underlayment is typically made up of layered polypropylene, which is itself a waterproof material. For example, Epilay’s synthetic products are a 4-ply underlayment featuring 3-ply cross-woven coated polypropylene, plus an additional layer of non-woven polypropylene.
Downsides to Felt, Advantages with Synthetics
As mentioned, asphalt roofing felt just isn’t as durable as synthetic underlayment. It’s prone to deteriorating more rapidly with time—and in storm conditions, it tears easily. When you’re installing it, it’s harder to install it smoothly, and wrinkles make the material less effective and even more prone to damage. Overall, roofing felt leads to less protection for the roof deck.
That contrasts sharply with synthetic underlayment, which is designed for improved performance in each of these areas. Synthetics are made to last longer, even when exposed to sunlight (which breaks traditional felt down very rapidly). In high winds and storm conditions, synthetic underlayment performs much better because it features high tear strength. It’s easier to install, too—and rolls out without wrinkles that can cause damage or make it prone to lifting in high winds.
By the Numbers: How Cost-Effective is Synthetic Underlayment?
According to Fixr, the national average price per square foot for felt underlayment is between $0.05 to $0.50. Synthetic tends to be a little bit higher at $0.17 to $0.55 per square foot. In general, thinner synthetic underlayment tends to be about the same price as felt underlayment, but it has a longer lifespan and vastly increased durability. Thicker synthetic underlayment and peel-and-stick underlayment are more expensive, but also a lot more durable. With peel-and-stick products in particular, you can create a barrier that is completely impervious to water.
So in terms of cost-effectiveness, which is better? Synthetics win on that front—and it’s not because of the initial investment, but because of the lifespan.
Consider this: Traditional felt underlayment is typically rated to last between 12 and 20 years. This means that after about a decade, the underlayment starts to deteriorate, and that makes it much more prone to leaks. Homeowners will need to start thinking about replacement.
Meanwhile, synthetic underlayment is made to last a lot longer. Epilay’s thinnest product, PlasFelt, features a 10-year limited warranty—and a lifespan that is likely to far exceed that warranty since synthetic underlayments last on average between 25 and 35 years. At the other end of the spectrum, ProtecTite Platinum offers a 40-year limited warranty—the warranty alone is nearly four times the lifespan of roofing felt.
In other words, using synthetic underlayments means saving money over time because it extends the lifespan of the roofing system by quite a lot. It may cost slightly more as an upfront investment, but for that investment, homeowners can get up to four times the lifespan out of the roofing system before worrying about replacement.
At the end of the day, cost-effective synthetic roofing underlayment is the way to go, not only because it saves money, but because it does offer better protection and a whole host of other benefits like easier installation, greater resistance to UV rays, and more. Try it on your next roofing project, and you’ll see the difference! Contact us today to learn more.