Step Roof Flashing Details

Step flashings are to be installed one per course.

Step roof flashing details.

Step flashing is a rectangular piece of flashing bent 90 degrees in the center. Step flashing fits to each course of shingles and appears to step up the wall of the chimney. Wind driven rain and snow can penetrate between step flashing pieces and wet the sidewalls and the roof. The length of each piece of cap flashing varies with the pitch of the roof.

Flashing typically consists of 1 step flashing which is attached to the roof 2 cap flashing which is attached to the chimney or a wall figure 10 2 3 drip edge flashing and 4 valley flashing. The shape of vent flashing is typically a cylinder with a wide flange at the base which is lapped into the shingles as the roofing is installed. Step flashing redirects the water back onto the shingle. Even if one piece of step flashing fails the flashing and shingle below it start the process over again.

The roof deck flange of step flashings are to be fastened to the surface of each shingle in a position whereby the next course of shingles will cover up hide the flashing from view. The base flashing extends a minimum of 4 up the wall and onto the roof. We ask for 6 inches up the wall. Vent pipe flashing fits over flues or pipes.

It is used for roof to wall flashing. That lip is then set into a reglet or groove in this case cut into the mortar joint of the brick wall above. Step flashing is sometimes called base flashing and cap flashing is sometimes called counter flashing. Multiple pieces of the flashing will be installed in layers with shingles to ensure the water flows away from the wall.

Continuous flashing against a sidewall is one way to install a roof but it s not the correct way. It may seem as if a single piece of flashing would offer more protection than many pieces of step flashing. Step flashings are interwoven with the shingles and act essentially as shingles with an upturned leg to allow a transition of the vertical drainage plane of the wall to the drainage plane of the roof. It is used for roof to wall flashing.

The vertical flange of the flashing is to extend up behind the adjoining siding. One common method is to lay the edge metal under the eaves membrane and over the rake. The reglet is filled with sealant. No step should be more than 3 bricks high.

So we instruct our roofers to run the ice barrier membrane and the roof underlayment up the sidewalls. Proper roof wall flashing example 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.