Profile sheet roofing Is one of the good method for waterproofing, but the slide rain can cause water to sweep on the slab throught the parapet walls, to overcome this possibility and attain 100 percent waterproofing for the top floor we have a combination of roofing and fixing App modified membrane on the outside of the parapet wall bringing it down till the beam level. Unlike waterproofing paints Membrane can remain on the vertical wall for a very long time.