Roof Flashing Vs Counter Flashing

Counterflashing is the piece of metal that is applied to the masonry wall designed to shed water off of the wall and down onto the roof surface.

Roof flashing vs counter 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. The roof side of the copper is cleated to the nailable cant strip. The base flashing is designed to accommodate building movement. It is used for roof to wall flashing.

Controversial changes get people and the building industry thinking which is what happened recently with the way code looks at sidewall flashing in asphalt shingle installations. This final layer is called counter cover or cap flashing and commonly consists of aluminum galvanized steel copper tin or even plastic. Depending on the construction situation a step flashing roof is sufficient. Such a system usually consists of copper counterflashing and base flashing in conjunction with roof composition flashing or coping.

The roof composition flashing extends up the cant strip over the coping and part way down its face under the copper flashing. In this case continuous flashing is simply a single piece of flashing placed behind the exterior cladding and weather resistive barrier on the wall and then extended out over the shingles. It laps the composition flashing at least 4. Placed opposite to base flashing or above base flashing counter flashing completes the two part team.

On the opposite side a continuous copper edge strip is attached to the coping and the lower edge is bent to form a drip. Step flashing is a rectangular piece of flashing bent 90 degrees in the center. Vinyl siding can double as counter flashing as long as the step flashing goes underneath it. The counterflashing diverts water to the base flashing which in turn diverts it to the composition flashing.

Is that counterflashing is construction formed metal or elastomeric sheeting secured on or into a wall curb pipe or other surface to cover and protect the upper edge of a base flashing and its associated fasteners while flashing is roofing components used to weatherproof or seal roof system edges at perimeters penetrations walls expansion joints valleys drains and other places where the roof covering is interrupted or terminated.