Picking the Best Metal Roof Underlayment for Your Home

Every kind of roof offers its pros and cons, but almost no roof is what it seems to be on the surface. If you’ve been looking for a roofer in Cranberry Township, PA you’ve probably read tirelessly about the vast array of roofing materials that you can choose from.  Depending on the materials your roof is made from, you’ll also have to install underlying materials to ensure that the roof is properly protected against water, temperature, vapors, and debris. The quality and performance of your metal roof underlayment is an essential component to your roof’s efficacy and longevity.

The roof underlayment is the first line of defense against these different threats to your home. It lies between the covering materials and the roof deck. Besides shielding your home from weathering, it also helps give the roof its even and consistent shape, and protects the roof covering from wearing against the fasteners used on the roof deck. This underlayment is so critical to the performance of your roof that it’s oftentimes mandated in your roof covering’s warranty. This means you want to pick the best underlayment for metal roofs that you can find.

Synthetic Roof Underlayment vs Felt Roof Underlayment

Roof Underlayment

Traditional roofs use an underlayment made of felt. While inexpensive, this outdated choice doesn’t offer nearly the same advantages of more modern synthetic roof underlayment materials. Felt does little more than to offer some rudimentary water protection, and to act as a source of backup if the roof itself is damaged or failing.

Felt was a more useful choice when roofs were commonly made with natural wood materials that would leak sap. The felt was great at catching the sap and preventing it from seeping into the house and causing damage. However, these days, modern roofers use stronger materials and woods that don’t bleed. As a result, this primary benefit of felt roof underlayments is rarely relevant to homeowners today. With that said, regular roof inspections are still important.

Quality of Materials

Synthetic roof underlayments are the best choice for your new metal roof. Synthetic underlayments are often much, much lighter than felt underlayments. #30 felt is made from asphalt materials, so it’s naturally very heavy. The best synthetic metal roof underlayments can be up to ten times lighter than felt.

Because they’re lighter, synthetic roof underlayment rolls are a lot bigger per piece. This means you won’t need to buy as many individual pieces, and you’ll need to make fewer trips up and down from the roof. This saves time and helps preserve your safety.

Felt has another major downside; it’s not at all fireproof. Felt roof underlayments won’t do anything to help stop the spread of flames if your home or roof catches fire, while many synthetic roof underlayments are made with fire safety in mind (and come with a Class A fire resistance rating).

These tend to be better at sealing openings, gaps, and spaces around fasteners and other breaks in your roof covering and roof deck. Felt isn’t always very watertight in these areas, meaning the very underlayment itself could be responsible for that pesky roof leak you’ve been trying to track down.

Fitting the Underlayment to the Metal Roof

Roof Synthetic Underlayment

Installing a synthetic roof underlayment is far quicker and easier than felt. Felt, being up to twenty times weaker in its structural integrity than synthetic materials, shreds easily under strong winds; if your roof is subjected to a violent storm before your repair or installation is complete, your contractor may be delayed quite a bit in repairing the damage, resulting in enormous costs on top of your already-steep estimate for the job.

Synthetic underlayments install easily and lay flush against the roof deck; they don’t crease or crumple, unlike felt materials, which aren’t as pliable and workable. Rolls of felt are also rather narrow, meaning it takes more labor to put them up than the wider synthetic rolls.

While felt is very easy to tear, that also makes it easy to cut. But, you’d rather have the durability of synthetic, which you can quite literally walk on top of. Leave the dirty work to your contractor, and have them do the work of cutting synthetic rolls. The added protection is well worth the extra cost.

Weather & Damage Resistance

Synthetic underlayments are great for handling the extreme changes in temperature that we experience in Pittsburgh, but felt roof underlayments can’t adequately handle temperatures outside of the comfortable ranges.

Plus, synthetic underlayments can withstand UV radiation for six months to a year before they begin to deteriorate, while felt underlayments begin to deteriorate the moment they’re exposed to ultraviolet rays.

And, weathering isn’t the only type of damage to be concerned about. If your home has ever been plagued by pests or rodents, then you know the value of keeping them on the outside. A felt roof underlayment is easy for bugs and other varmints to chew through. Plus, it can be conducive to mold and fungi. A synthetic roof doesn’t suffer any of these issues; it’s too strong for pests to penetrate, and it’s water resistant, so unlike felt underlayment, it doesn’t mildew and mold.

Making the Decision

While the best metal roof underlayment you can choose is a synthetic one, they are a little bit pricier than traditional #30 felt underlayments by about 10%. However, this cost is quite worth the value that you get out of the extra protection afforded by a synthetic roof underlayment.

Plus, as the oil refining process continues to be optimized, the crude oil sediment that asphalt is made from is less present in the oil itself, making the material more scarce. It’s possible that processed asphalt material prices will begin to ascend, while the process of developing synthetic underlayment materials gets cheaper and cheaper.

All things considered, synthetic underlayments are the clear choice for numerous reasons:

  • Stronger and longer-lasting
  • Superior fire protection
  • Workable material, doesn’t crease, available on larger rolls than felt
  • Resistant to weather, fungust, and vermin
  • Projected to become more affordable over time

If you’re ready to get a new roof put on your home, and you want to learn about the best underlayment for your metal roof, get in touch with your friendly neighborhood contractors at Gotcha Covered Contracting. We’ll give you a fair estimate on your new underlayments to help you make the most informed decision you can.

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