How to Install Ice and Water Shield on a Shingle Roof

What is ice and water shield?

In this video I’m gonna show you how to install ice and water shield in your valleys. In California, we don’t install ice and water shield around the eaves, we just install them in our valleys and around penetrations. This is an important step to extend the life of your roof, and as an Owens Corning Platinum contractor, this is one of the things that allows us to provide the Platinum Warranty to our customers.

Ice and water shield is essentially a self-adhered membrane. It has an adhesive backing, and it’s also thicker. This provides additional defense and additional waterproofing capability in our valleys, which are one of the most vulnerable components and areas of a roof.

Which should you install first, underlayment or ice and water shield?

You can see here, we’ve already got our underlayment installed. The reason for this is, when we install our ice and water shield, we want to make sure that we’re coming on top of the underlayment as well as on top of the drip edge. Just like any other shingle roof or any other component, we want to make sure that our water rolls off on top of the underlayment. So if you have an area like this where you have your valley that’s terminating into the field of the roof, install your underlayment all the way up to your valley, then you’ll install your ice and water shield on top of that. And also, like I mentioned, you want to make sure you get your drip edge flashing installed so your ice and water sits on top of that as well.

How to align and install ice and water shield in a roof valley

So we’ve got our ice and water shield in place right now. We want to align it to have the center in the valley. Then we can start cutting along our edge. We’re also gonna come up on top past the peak of our valley, and make a slit here as well, to be able to fold it to the other side. So we’re cut flush with our drip edge here, and on this side we’re flapping on the other side of the valley so when we install this piece of ice and water shield, we’ll flap on this side and have a nice hermetic seal all around.

We’ve got our ice and water shield aligned here. We’re just gonna take the film off here, and start pulling it. You don’t have to flap it back. You can just pull it like this, and it’s as easy as that. If you don’t lift it back, you don’t lose alignment. So just pull it off here, you can just tap it into place, and make sure you’re properly adhered. And we’re gonna do the same thing on this side. Again just grab this film, making sure we don’t lose our place in the valley.

We’ve cut flush with the drip edge, we have a nice, snug corner, and we’re ready to install the other side.

Layering two pieces of ice and water shield

So we’ve got our first piece of ice and water installed on this side of the valley. And you can see how we flapped over here. We made our slit here. Now when we install our second piece, we’re gonna flap over this way so that this corner will be nice and tight and we won’t have any issues with waterproofing. Again we want to make sure that we’re aligned here with our valley, the center of our valley. Again, just pull that film off gently. You have a little bit of working time with this, but if you wait any more than 5-10 minutes and it’s a hot day, it’s gonna fully adhere. So you want to make sure you’re properly aligned before you start installing. We’re tight on the valleys here. And as the sun heats this up, it’ll start adhering here. So we’re all done with this, and we’re ready to install our underlayment on top of it.

Alright, we’re done now installing our drip edge flashing, our ice and water shield, and underlayment. We’re ready to get started with the shingles. This was a lot of work that went into it. One thing I want to really emphasize at this point is always make sure to take safety precautions into account when roofing. Whether you’re harnessing off or installing toe kick boards, in these demonstration videos we’re not doing those. Because the point of these videos is to install—the proper way to install, but always make sure you’re following local codes, and most importantly, be safe on a roof.