Walthamstow.London - basement waterproofing mississauga http://walthamstow.london/News/basement-waterproofing-mississauga-2/ This process involves excavating and sealing from outside. These are more traditional methods of waterproofing. The walls are sealed with a combination of heavy duty (trowel on) tar, and asphalt membranes. Delta membrane or high density Styrofoam (SM) is used to insulate the sealing products. Fri, 02 Dec 2016 11:18:04 UTC en