Roof Valley Sealing

The roof covering of a home is one of the single most important aspects of home construction. The roof has many responsibilities we heavily rely on, such as protection from exterior elements, moisture run off management, and a thermal energy barrier, just to name a few. Because the roof is such an integral part in the home construction process, it is very important to ensure that roofs are installed properly and well maintained to ensure the longevity of a home.

A roof surface consists of multiple different parts such as hips, ridges, and valleys. All of which play a vital role in the functionality of the roof system as a whole. Though each part of the roof is important in proper moisture run off management, the valleys of the roof are likely to experience higher volumes of moisture than others by design. A valley is formed where two roof slopes meet, creating a channel for moisture to flow down to the gutter system below.

There are three main types of installation techniques to choose from when roof valley coverings are installed: closed, open, and woven. The name of each installation is correspondent to the way in which the valley is installed and presented. A woven valley consists of interlacing the shingles over the valley to create a seamless look. A closed valley is where the shingles extend through the valley so the roof surface covers or closes the valley area. An open valley consists of self-adhering underlayment that is installed over the roof valley surface followed by a pre-bent metal lining that is fitted in the valley with the adjacent shingles overlapping the metal edge. No matter the style, these areas are more prone to leaks and moisture damage if not properly sealed.

Sealing of the valleys is one of the most integral parts in ensuring maximum protection in these areas against potential water leaks. This is ensured by applying a continuous self-sealing bituminous membrane along the entire length of the valley before the installation of underlayment or shingles. The roof cladding is then installed and the materials for the corresponding valley type follow. Though a self-sealing bituminous membrane should be the base sealing standard for all types of roof valleys, some valleys, such as open valleys, require additional sealing at the shingle edges to prevent moisture from entering beneath the shingles, which is called “crosswashing”. This installation technique can also be beneficial in wind uplift resistance as well. Because sealing is not always visible, it is important to ensure all work done to your roof is high quality and professionally done to ensure a long-lasting healthy home. You can find out more about roof valley sealing in the video link below.