Parapet Wall Roof Leaks

Don t seal the parapet rain the primary source of water is driven by wind through permeable masonry units mortar joints and cracks in the wall.

Parapet wall roof leaks.

If the cavity drains freely water should move down to the lower levels of flashing and drain from the wall. Water from either of these locations may bypass flashing and enter the backup wall directly. It is the wind pressure that causes the majority of wall leaks not water flowing down the wall. 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.

There are other common causes for leakage at parapet walls. On the other hand the roof doesn t know which direction the rain is coming from. Water may be entering the coping at the top of the parapet or entering the roof side of the parapet. This new torch on flat roof is leaking because the parapet walls and the coping stones are defective water damage to the ceiling below from the leaking ceil.