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.
The parapet walls around the roof also have these seams.
On the other hand the roof doesn t know which direction the rain is coming from.
Seam separation is a common issue with traditional roofing materials.
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.
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.
Water may be entering the coping at the top of the parapet or entering the roof side of the parapet.
It is the wind pressure that causes the majority of wall leaks not water flowing down the wall.