Fasteners placed in the exposed center area.
No flashing in valley of roof.
Only nail at the edges with only enough nails to hold it in place.
Roof mastic applied along sides of valley flashing.
Roof flashing is a thin sheet of galvanized steel installed to channel rainwater away from important areas of the roof.
Avoid the following common errors.
The edge of the roof has thin metal flashing that helps water drip off the roof without damaging the home or causing a leak.
In this open valley style the shingles over each section of roof do not touch.
Metal valley flashing is installed over the underlayment but under the edges of the shingles.
While some skylight manufacturers include flashing in their products sometimes roofing professionals have to create it or purchase it separately.
Closed cut valley fully replaced with new metal valley flashing.
Drip edge metal valley flashing dormer chimney and kickout flashing are types of roof flashing that shed water away from the connections between roofs walls chimneys and other building assemblies.
Failure to extend the entire width of the metal valley flashing beyond the eave of the roof.
Extra nails may increase the risk of leaks.
Moving up the valley install any additional roof flashing as required to cover the entire length.
Open valleys have metal flashing to protect this critical area of the roof.
They are installed to overlap and form a gap that exposes the valley flashing.
Punctures in the center of the valley.