Should Ice and Water Barrier Be Installed in the Valleys of a Roof?

Installing an ice and water barrier in the valleys of a roof is highly recommended. Valleys are areas where two roof planes intersect, creating a channel for water flow. These areas are particularly vulnerable to water infiltration, especially during heavy rains or when ice dams form.

Installing an ice and water barrier in the valleys provides an additional layer of protection against water penetration. The barrier acts as a waterproof membrane that helps prevent water from seeping through the roof deck and into the underlying structure in the event of ice dams, wind-driven rain, or other forms of moisture.

Here are some key points to consider regarding ice and water barrier installation in valleys:

1. Proper Coverage: The ice and water barrier should extend up the valley at least 24 inches on each side from the centerline, or as specified by local building codes. This ensures that the entire valley is adequately protected against potential water infiltration.
2. Proper Sealing: The ice and water barrier should be applied with careful attention to ensure proper sealing. The edges of the barrier should be tightly sealed to adjacent roofing materials to create a continuous barrier that prevents water from bypassing the membrane.
3. Installation Best Practices: It is important to follow manufacturer guidelines and industry best practices when installing the ice and water barrier in valleys. This includes properly lapping the membrane to ensure water flows smoothly down the valley and avoiding any gaps or wrinkles that could compromise the effectiveness of the barrier.

By installing an ice and water barrier in the valleys, you add an extra layer of protection to this vulnerable area of the roof, reducing the risk of water infiltration and potential damage. It’s advisable to consult with a professional roofing contractor to ensure proper installation and adherence to local building codes and manufacturer recommendations.