Open Or Closed Roof Valley
Closed valleys protect the roof lining from abrasion that water run off would cause and are therefore quite durable options.
Open or closed roof valley. Open valleys are excellent for preventing moisture from entering through the lining and protecting your roof from the humidity of the outside air. And while some homeowners may prefer the aesthetics of a closed valley the heavier and thicker the shingle the less likely it is to lie flat across a joint. Repairs to closed valleys are a lot more involved than working on an open valley as is re roofing or making changes to a portion of your roof in the future. Open valleys may be susceptible to water backup if the cut off shingles are not properly trimmed potentially causing roof leaks.
An open valley can easily and quickly shed ice and water. However open valleys may be susceptible to water back up along the top of the cut off shingles in the valley if not properly trimmed potentially causing roof leaks. A closed valley is where the tiles or shingles are butted up against each other in the center of the valley. An open roof valley meanwhile is a flashing method in which a sheet of pre bent metal is installed after the valley lining is placed.
The main advantage of closed valleys is that they protect the roof from snow and ice build up however in florida this is not an issue that needs to be considered. The metal is usually pre painted to best complement the shingles color blend. If you have a shingled roof as most torontonians with a sloped roof tend to have then you will have one of two kinds of valleys on your home. Although the open valley is recommended by the manufacturer closed valley is acceptable.
The roofers apply the shingles cutting and sealing the ones that overlap the metal. The closed variation is a flashing that has been completely covered with shingles while in the open variation will have the flashing completely exposed to the elements. However it is said that provided the rest of the roofing shingles were properly installed and are performing properly open valleys will perform better over time than closed valleys. The only type of valley that is unacceptable is the woven valley.
It is always a good idea to check with the manufacturer or a certified installer of the product such as ourselves. An open valley has a gap usually about 6 inches between the tile or shingles at the valley area.