How To Flash A Flat Roof To A Vertical Wall

Step flashing on roof peak.

How to flash a flat roof to a vertical wall.

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. Details concrete masonry roofing wrb flashing. Protect the eave from ice dams and sideways rain step one in steep slope roofing is the edge flashing. Gravel stop flashing helps protect the fascia from water damage just like the drip edge.

Bend the corner flashing tightly around the corner. The roof flashing is then placed up behind this through the wall z bar flashing on the outside of the vertical blocking backing material. 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. 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.

I fold a piece of metal flashing for the inside corner between the subfascia and the wall. That lip is then set into a reglet or groove in this case cut into the mortar joint of the brick wall above. 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. Most simply use a nominal 6 piece of lumber.

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. And when the flat roof is below the sloped one flashing is applied on the flat one and extend upwards to the slope. One common method is to lay the edge metal under the eaves membrane and over the rake. Strips of the roofing material itself are sometimes installed before the membrane attached to the roof perimeter and the vertical surface.

The exterior wall covering material is then kept off the surface of the roof. Long helps it to fold onto the roof sheathing. The gravel stop prevents material on the roof from falling off and also serves as a shield to protect the roof from damage. At roof to wall intersections see figure 1.

Use step flashing that has a 2 to 4 inch longer vertical leg than normal. Use flashing cement at joints to help secure flashing. A vertical cut about 2 in. 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.