How To Seal Bitumin Roofing On A Parapet Wall

Proper roof wall flashing example.

How to seal bitumin roofing on a parapet wall.

Bituminous sheet products are used to waterproof flat roofs basement walls and to line earth dams and canals. 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. Center it atop the wall so each side extends outward in equal amounts. 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.

The installer tacked a row of asphalt shingles to the wall caulked their top edge and hoped for the best. It is the wind pressure that causes the majority of wall leaks not water flowing down the wall. On the other hand the roof doesn t know which direction the rain is coming from its function is. The flat roofing material must go up the wall a minimum of 12 or up the wall and over the top of the wall if the wall is less than 12 high.

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. Liquid systems and putties including acrylics solvent based bitumens and water based rubberized acrylic modified bitumens which are used to seal parapet walls small flat roofs roof bolts flashings and ponds. Plaster and mortar are very porous and absorb moisture the same way a sponge would so even a small crack on the top of a parapet that allows water into the wall may result in peeling or damaged paint. Roll out bitumen flashing atop the wall from end to end with the self adhesive backing paper facing down.

Here is an attempt though maybe not a very good one to make the roof flashing serve also as a through the wall flashing with a tile roof.