This is a granulated roll installed in three feet sheets it is mostly used on commercial flat roofs and is well adapted for residential application especially dead valleys or other troublesome spots.
Flat valley roof.
Building a flat roof valley is no different than a plumber installing a drainpipe that is flat for a few feet just to accommodate some aesthetic feature.
We love the flexibility of a flat roof for certain design limitations but they have a bit of reputation for leaks and repairs.
A valley roof leak is the most common type of roof leak.
Repairing a dead valley isn t really a diy project for most homeowners.
A roofer must be careful where the nails are placed in the shingles of valley roofs.
The roof design is as essential to the proper function of a house as is the foundation plumbing or electrical design.
The valley area of a roof the straight lines formed when two different planes of the roof meet is a critical area that handles a tremendous amount of water run off.
Gaf mastering the roof chapter 12 this video demonstrates the proper installation technique for installing roofing valleys.
Valleys are created where two roof slopes meet.
Woven closed cut and open.
A roof valley is formed where two roof slopes meet.
There are two basic types of valleys.
If the nails are placed in the very center of the valley leakage will occur.
Also different architectural styles will use the same type of roof.
Valleys are a prime leak area so it s important to be careful.
Water like to follow the valley to the edge and flow back under the valley.
Of course flat roofs are not flat but have a very slight roof pitch of between 1 4 to 1 2 per foot.
Essentially there are three main ways to shingle a roof valley.
The open woven and closed cut methods are demonstrated.
These leaks can be caused by poor roofing practices or just simply by the age of the shingles on the roof.
Valley areas are prone to leak due to the lack of using proper materials.
When a valley is flat like this one in the image it is more problematic.
Valleys are typically found where gable dormer roofs meet the main roof or when a house has angled wings or additions where two roof sections in different planes meet.
Your choice of valley installation method is critical because when improperly installed valleys are risks for serious leaks.
Water collects in a valley to flow off the roof.
Despite this flat roof valleys should never be built.
Intricate roofs have many parts that incorporate several of the basic roof designs such as a gable roof sitting atop a gambrel or variations of the gable valley roof design using one or a variety of different types of roof trusses also see our very detailed diagrams showing the different parts of a roof truss.
