Устройство примыкания для битумной черепицыОпубликовано: 07.10.2008
Installing step flashing
Installing step flashing correctly is one of the first things I teach a new member of my crew. The first rule of flashing is that water runs downhill. The second rule of flashing is that sometimes rule No. 1 isn’t the whole truth and that water also runs uphill, as when it wicks up inside debris or backs up behind ice. For this reason, I like to lap all flashing by at least 2 in.
It’s important to remember that a building always is moving. If you nail step flashing to the wall and to the roof, you’re asking for trouble. Most of the time, I like to avoid putting any extra holes in the roof surface, so I nail step flashing to the sidewall only, where both the next piece of flashing and the siding will cover the nail head. The bottom corner, where you start the course of flashing, is made from two pieces of bent step flashing lapped over each other and caulked in place.
Corner flashing comes first
Lay a bead of sealant. Where the next piece of flashing will overlap,
apply a bead of caulk to seal the corner. This spot is prone to leaking
because there is not a full 2 in. of overlap. Use a sealant designed
for roofing. Not all caulks can withstand the heat and exposure of
being on the roof.
The flashing alternates with the shingles
Bend the first piece along the plumb line. The first piece of step flashing needs one bend so that it laps cleanly over the corner flashing installed in the previous step. Make sure the caulk joint between these two pieces is bedded evenly. Then sink one nail into the sidewall to hold the step flashing in place.
Begin the weave. With step flashing, you do a little flashing, then a
lot of roofing, then a little more flashing, and so on. Each piece of
step flashing laps over the shingle below and under the shingle above.
The bottom edge of the flashing should extend just below the nail line.
Attach each piece with a single nail high enough to be covered by the
next course of flashing, the building wrap, and the siding.