Posted on: March 30, 2022

Ice & water shield is a self-adhering waterproofing underlayment used on a roof to prevent ice dams and wind-driven rain.

Where Is It Used?

In Northern Virginia, the most commonplace use of ice & water shield is on the eaves, valleys, around flashings, chimneys, and any other area where water can penetrate. In high wind areas, they can also be used on the rakes.

Preventing Ice Dams

When used on the eaves, it must go 2 feet past the interior wall. This can help prevent ice dams and water from getting into the home. However, preventing ice dams is a three-part system:

  1. Adequate insulation
  2. Ice & water shield
  3. Proper ventilation

An Extra Line of Defense

As mentioned before, it is also installed on the valley (where two different slopes come together). When it rains, valleys carry a large amount of water. If there is any damage to the shingles in the valley, water will find a way to get underneath. That is where the ice and water shield comes into play and earns its name.

We also install the ice & water shield under flashings and around chimneys. This is to help protect against wind-driven rain and anywhere the water may be backed up.