Flashing Roof To Wall Intersections

Thru wall flashing originates with a vertical leg in contact with the exterior sheathing tucked or shingled up under the house wrap and a horizontal leg that extends all the way through the masonry to the exterior surface of the wall.

Flashing roof to wall intersections.

Once the flexible flashing is set i apply a piece of housewrap along the wall where the fascia meets it. Proper installation of flashing and counter flashing at the intersection of a vertical wall with a roof surface is required to avoid roof leaks. The flashing extends up the wall at least 4. The metal flashing is formed with a hook edge and cleated on 12 centers.

Above the roof sheathing. Roof shingles should be installed over the portion of step flashing on the roof. I cut the tape so that it laps onto the housewrap above and 3 in. Install step and kick out flashing at all roof wall intersections to protect walls from water intrusion and install boot or collar flashing at all roof penetrations to protect roofs from leaks.

Most mason contractors are diligently installing flashing and weep holes at the base of walls as well as at the window head and sill. Our page top photograph illustrates a successful installation of flashing and counter flashing along intersection of a roof surface with the side of a brick constructed dormer. Step and kickout flashing should be installed at all roof wall intersections to protect the wall and divert rainwater runoff into a gutter. Flexible flashing tape seals the eave to the wall.

Do not seal housewrap or building paper to step flashing. I use a wide piece of flexible flashing tape to protect the area between the subfascia and the wall. At roof to wall intersections see figure 1. If the roof is metal or rubber membrane continuous flashing should be used rather than pieces of step flashing.

The flashing extends onto the roof a minimum of 2 inches 4 inches is preferable in more severe climate areas. Tape the top of step flashing with 4 inch wide minimum self adhering modified bitumen roof tape. Use step flashing that has a 2 to 4 inch longer vertical leg than normal. Kick out flashing should be installed at the end of a roof wall intersection to divert water away from the wall and into gutters.