How To Flash A Flat Roof To A Vertical Wall

Fastening strips or termination bars may be used to pinch the membrane down to the roof deck or into the bottom of the wall before the base and counter flashings are installed.

How to flash a flat roof to a vertical wall.

The exterior wall covering material is then kept off the surface of the roof. Bend the corner flashing tightly around the corner. To install the roof wall flashing above the builder bent the top edge of the flashing into a 90 degree lip about 2 cm in width. The roof flashing is then placed up behind this through the wall z bar flashing on the outside of the vertical blocking backing material.

That lip is then set into a reglet or groove in this case cut into the mortar joint of the brick wall above. If you do not wish to form your own corner flashing you can buy pre bent pieces and cut them to size or use a piece of corrugated aluminum which is easier to bend. Use step flashing that has a 2 to 4 inch longer vertical leg than normal. Two ways to flash roof edges.

Protect the eave from ice dams and sideways rain step one in steep slope roofing is the edge flashing. At roof to wall intersections see figure 1. When the flat roof as on a more elevated position compared to the sloped roof the flashing of the sloped roof extends onto the flat one. The gravel stop prevents material on the roof from falling off and also serves as a shield to protect the roof from damage.

Step flashing on roof peak. Tape the top of step flashing with 4 inch wide minimum self adhering modified bitumen roof tape. Gravel stop flashing helps protect the fascia from water damage just like the drip edge. One common method is to lay the edge metal under the eaves membrane and over the rake.

Roof shingle over step flashing. I then add a second piece of flexible flashing tape to cover the open corner of the metal flashing and i fold it down onto the subfascia. Use flashing cement at joints to help secure flashing. Long helps it to fold onto the roof sheathing.

I fold a piece of metal flashing for the inside corner between the subfascia and the wall. And when the flat roof is below the sloped one flashing is applied on the flat one and extend upwards to the slope. Strips of the roofing material itself are sometimes installed before the membrane attached to the roof perimeter and the vertical surface. When fitting cover flashings to a flat roof like the one pictured bottom right there is no need for the third covering angle of lead the lead is simply cut just above the flat roof to stop capillary action and the flashing cutting into the flat roof itself.