Roof Leak Where Siding Wall Meets Roof Line

Improper installation of flashing where roofing shingles meet vinyl siding.

Roof leak where siding wall meets roof line.

Some roof leaks happen at step flashings. So let s look at the ten of the most common culprits in causing your roof to leak and what you can and should do about them other than recruiting a bucket brigade. Installation gaps in siding of any type if not back flashed invite leaks into the wall above left. You find these flashings where a roof climbs alongside a vertical wall.

Roof leaks can ruin insulation become a breeding ground for black mold damage interior ceilings and walls and rot the wooden framing. Part of the flashing turns up on the wall and the other portion gets covered by the next row of shingles. When each row of shingles was installed a step flashing was put next to the wall over the shingle and then covered by the next shingle row. Even if the roof has been properly flashed against the sidewall this one hasn t water can still run down the side of the house and behind the siding causing rot.

And in our experience when a single piece of flashing extends only a few inches under the shingles especially on a long roof slope and worse on a roof that happens to slope slightly towards rather than away from the abutting vertical building wall the accumulated roof drainage water near the bottom end of the roof wall intersection will overwhelm the width of the flashing and because it is not directed back out on top of successive shingle courses it leaks into the building or building. The intersection between a roof and a sidewall can be a rot problem waiting to happen. Part of the flashing turns up on the wall and the other portion gets covered by the next row of shingles. You find these flashings where a roof climbs alongside a vertical wall.

You should only be able to see a tiny bit of the flashings if they were installed correctly. Someone at the build site used sealant on an area where the roof meets the side of the house in an attempt to fix the issue. Structural movement or damage shown in a more extreme case at above right can also allow significant leaks into the building. The wall water has to be getting behind the siding along where the garage meets the house.

Some roof leaks happen at step flashings. As each row of shingles is laid a step flashing is installed over the shingle next to the wall. Problem 2 water is entering the top of the window then running down the interior right side of the window frame. See siding fiber cement gaps.

I made this video this morning and i hope it help explain the flashing wall detail where the siding meets the roof. At the point where a roof meets a vertical wall you will see step flashings.