There are lots of different factors to consider when choosing a roof underlayment, and one of those factors should be the tear strength of your chosen product. With Epilay’s PlyStik peel-and-stick underlayment, the 48-mil thickness helps increase tear strength, as does the 5-ply design, which features three layers of cross-woven polypropylene, a layer of non-woven polypropylene, and a layer of SBS modified bitumen. Other underlayment products, such as Protectite Superior, feature a tear-resistant 4-ply design with 3 layers of coated cross-woven polypropylene and a layer of non-woven polypropylene.
So why is high tear strength important? There are several reasons. Find out more below!
High Tear Strength Leads to Easy Installation
One good reason to choose an underlayment with high tear strength? It makes installation easier—and there is less wasted material once the job is done. If you’ve ever used traditional felt, you’ve probably discovered that it has a habit of tearing around fasteners as it’s being installed. You need to be careful with it—and if the tears are large enough, it can compromise the purpose of the felt, which is to help protect the roof deck from moisture. Synthetic products don’t come with these headaches. They’re tough enough to stand up to screws, nails, and staples without tearing.
Tearing around fasteners isn’t the only installation-related damage to worry about. When working with roofing felt, contractors need to be careful about walking on it. Step wrong or slip a little, and the felt could tear. With synthetic underlayment, not only does the high tear strength prevent this type of damage, but skid-resistant surfaces also help prevent slips that lead to tears in the first place.
Better Protection Against Wind Damage
Another great reason to consider synthetic underlayment is that the high tear strength of synthetics is better able to protect the roof deck while the roofing is being installed. With roofing felt, once the felt is installed, shingles or the roofing of your choice needs to be installed over top of it immediately so that the felt doesn’t tear in high winds. If for whatever reason, you experience a delay between installing the underlayment and the top layer of roofing materials, the tear strength and wind resistance of synthetic underlayment will keep the roof deck protected from wind and storm damage until the job is finished.
Better Cold Weather Installation
Cold weather doesn’t exactly cause traditional felt to tear—but it does cause it to crack when you unroll it. That’s because the asphalt tar stiffens up when it’s cold outside. If you’ve ever had to do an emergency roofing job in the winter, then you probably know just how much of a chore it can be to unroll stiff rolls of roofing felt.
Synthetics don’t suffer from this problem at all. They don’t get stiff and hard to work with in the cold—and even if they did, the high tear strength that they feature would prevent them from cracking.
How do Epilay Products Stack Up?
So just how much tear strength do Epilay products have? To start with, they’re tested against ASTM D4533 standards, which is a type of test in which pieces of material (in this case, underlayment) are pulled apart to see how many pounds of pressure it takes to make the material tear.
Here are the results:
- Protectite Platinum’s tear strength rates up to 57 pounds of force
- Protectite Ultra’s tear strength rates up to 21 pounds of force
- Protectite Superior’s tear strength rates up to 17 pounds of force
- Protectite Plasfelt’s tear strength rates up to 20 pounds of force
As you can see, this is quite a lot of tear strength. Combined with tensile strength and other factors, these underlayments can stand up not only to the rigors of installation without tearing, but also to the kinds of wind uplift that would normally rip asphalt underlayment right off a roof.
Curious to see how Epilay products compare to 15 and 30-pound roofing felt where tear strength is concerned? Then check out the video below where we demonstrate the difference!