Anatomy of a Roof System: Roof Ice and Water Shields

Ice, Ice (and Water) Baby

Bet you never thought your roof could have so many moving parts, right? Well, they do and we’re here today to discuss ice and water shields, what they are, and why you need them.

What Are Ice and Water Shields?

Simply put, ice and water shields are waterproof membranes, aka underlayments made of polymer-modified bitumen, used to protect your roof decking from the elements, specifically ice and water. In Texas, we don’t get a ton of winter storms, but when they happen, they happen big, so you need these babies. 

What Happens if You Don’t Have Them?

When winter storms hit, ice dams can form. This is a serious problem. Here’s a look at the chain of events that causes them: 

• • It snows, and your yard is transformed into a winter wonderland. You make hot chocolate, and all is right with the world.
  • Then, the snow starts to melt because of the heat that escapes from your house or because of the backup of frozen slush from your rain gutters. 

• After that, melted water flows under the snow and freezes when it reaches the unheated soffit and eave areas of your roof, which creates an ice dam.

• All of the above forces water under your shingles and into the attic, which can damage your home: your ceiling, walls, and so on.

How Do Shields Work?

These important roof materials are, like we said, made of polymer-modified bitumen, but they also have an adhesive back surface that’s covered by a release film. During installation, the release film is removed so that the membrane sticks to the roof decking. This creates a watertight barrier when the shingles (or whatever roof you fancy) are installed. You need this. They’ll give you superior, top-notch, and time-tested protection against all the chilly fury that Mother Nature can unleash.

Where Do They Go?

The best places to install ice and water shields are on and around roof valleys, penetrations, overhangs, as well as dormers, skylights, vent stacks, chimneys, and on roofs that have 2/12, 3/12 or 4/12 pitch. So lots of places.

Three Types of Shields

So now that you know what ice and water shields are and what they do, let’s look at your options.

1. Granular. Also known as “sand surface, this one is the thinnest of the three types and it’s used in roof valleys. But just because it’s thin doesn’t mean it doesn’t hold up. It does.
2. Smooth. This type is mostly used on low-slope roofs, those with pitches that are 2/12, 3/12 or 4/12.
3. High Heat. Made of cotton-like fibers, this one is used (for the most part) on metal, slate and cedar shake roofs. 

The Calm Before the (Ice) Storm

Rather than waiting until you’ve got ice dams on your roof and are all worked up, it’s best to make sure you have ice and water shields now. If you already have them, now is also the right time to check on them to see if they’ll hold up come winter.

Peak has got you covered with ice and water shields—and anything and everything you need for your roof. We’re a family-run business and have been in Texas for many years, so we know all about our crazy weather. If you need us, just get in touch and we’ll be out your way in no time.