What is a leak barrier on your roof, and why is it important?

Most homeowners assume a roof is a roof. When you need a new one, a local roofing company peels off the old, tacks down the new, and you’re good to go. 

While that’s technically true, in very broad terms, there’s much more to it than that. And understanding what’s really involved can help you make a better, more informed decision when it’s time to install your new roof here in South Jersey.

Your roofing system is actually a very complex blend of products, materials, and safeguards, all designed to protect your home and fortify points of vulnerability. Think about just how much wind and rain your roof is exposed to, and now add in literal tons of snow, run-off, and moisture saturation. A quality roof system is multiple layers of carefully engineered and designed products, and it has to be installed by roofing professionals who are familiar with local codes and regulations, know which products are best, and can help you make a lasting investment.

Today, let’s talk about leak barriers. Glamorous or flashy? Not really, but they’re absolutely critical.

What is a roof leak barrier?

As you might imagine, rain is one of the greatest enemies of a dry, snug home. Wind-driven rain is the most dangerous, blowing horizontally and finding its way between your shingles.

And that’s where the leak barrier comes in. 

As your roofing company installs your roof, they’ll install a leak barrier underlayment along the most at-risk points. These can include:

  • Eaves
  • Rakes
  • Valleys (where two angles of your roof line meet)
  • Around chimneys
  • At points where fasteners are used, providing an extra level of protection and a firm seal
  • Low slopes where run-off is slower
  • Perimeter edges of your roof (more on this below!)

Does a roof leak barrier prevent ice dams?

We need to back up a second… What exactly is an ice dam? It’s a common issue in the wintertime, caused by water running down the warmer slope of your roof (that’s over your attic space), then freezing when it hits the outer edge along your eaves. This can be caused (or at least made worse) by a number of factors, including inadequate attic insulation. Regardless, these barriers pose a major risk of water intrusion if left unchecked, especially as water accumulates behind the ice dam and pools on your roof. 

Leak barriers do not prevent ice dams (there are other solutions for that), but they do drastically reduce the risk of water damage. And, they can help create a less hospitable environment for ice dams by keeping water from soaking into your roof and freezing as easily. 

Should you put a leak barrier over your entire roof?

There are different schools of thought on this, and some of it depends on your specific climate. If you live in a temperate area where winters are mild, it might not be as essential. If you live in an area where the colder seasons can be harsh and wet, a more extensive leak barrier offers valuable protection and peace of mind. 

The takeaway?

The best way to get the very most from your new roof is to work with a trustworthy roofing company. Take your time, make sure you thoroughly understand their proposal and job scope, and ask questions about their product choices. Including that all-important leak barrier!

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