New Jersey Home Inspector - New Jersey Home Inspections
Good flashing details are vital in keeping water out.
Flashings are installed to keep water out of structural areas. Flashings are installed where roofing materials change directions, at roofing joints, and at the intersection of two different roofing materials. Flashing materials are usually metal, aluminum, and copper. There are flashings present at roof ridges, at valleys, and a hip areas.
Valleys are areas in the roof structure that water will flow down because a change in direction exists. Valley flashings are usually metal and are sometimes covered with roofing materials so they are sometimes hidden from view. Other times the valley flashings are fully exposed and can be easily viewed and inspected. Valleys must be properly flashed because they are a very vulnerable area due to the large volume of water flowing down the roof valleys. Even a small amount of damage to the valley and to the flashing can create a significant water leak under the valley. I will be looking for roof valley and flashing defects when I perform your New Jersey home inspection.
Ridge flashings are used when the roof covering material is brittle such as wood shingles or cedar shakes. These brittle materials can not be bent over and installed at the ridge area like asphalt shingles can. Ridge flashings are usually metal. The ridge tends to be less vulnerable to water leakage because of its position at the roof top. Water is always shed away and down the roof. Leaking ridge valleys are less common then leaking valley flashings.
Pitched roofing to almost flat roofing flashings:
When a pitched roof terminates at an almost flat roof surface proper flashings are vital because of the potential for water leakage at this termination area. It is imperative that the lower sloped roofing material extends three feet upward on the pitched roof. This type of configuration where the low sloped roof membrane is extended provides the most reliable seal at this vulnerable termination.
New Jersey home inspectors look for flashing defects, damaged flashings, and missing flashings while performing home inspections. Another critical flashing area is the chimney flashing. The chimney flashing will keep water out of the area around the chimney where it comes through the roof.