Foam Roofing – The Most Effective Waterproofing System

Several key characteristics set polyurethane foam apart as an ideal waterproofing material. First, polyurethane foam is waterproof and does not absorb water. In fact, closed cell polyurethane foam is also used in flotation docs and hulls of ships to provide strength and buoyancy. Second, spray foam roofing is applied in one seamless layer of any thickness. On typical projects, a 1.5″ thick layer of polyurethane foam provides the primary waterproofing barrier. Compare this with tar & gravel, single ply, or other membrane systems which are much thinner (1/16″ to 1/4″) and are held together with many seams. In contrast, foam roofing provides a single monolithic and seamless waterproofing barrier. Third, spray polyurethane foam aggressively adheres to all surfaces forming a watertight seal. This characteristic is known as the “self flashing” nature of spray foam roofing. Chemically adhering to metal flashing at roof edges, vents, skylight curbs, and other roof features, polyurethane foam forms a watertight seal with everything it comes into contact with. The thick, seamless, and self-flashing nature of closed cell polyurethane foam render it as the most useful waterproofing material ever conceived of by high-technology.

Leak protection on flat roof with foam roofing
Dura-Foam roof protected from the elements

Improve Drainage on Flat Roof Areas

Material thickness on Dura-Foam roofs is custom contoured to improve drainage. Standing water on flat portions of roof surfaces becomes problematic as it causes structural sagging. Over time, sagging tends to get worse since ponds of water become heavier as they grow deeper. Closed cell polyurethane foam is the ideal material for filling low areas because it is waterproof and very light weight. By filling low areas, Dura-Foam provides a permanent solution to structural sagging caused by heavy ponds of water.

The images below are exaggerated cross sections of a typical roof structure which show how Dura-Foam applies additional closed-cell spray polyurethane foam to low areas of a roof surface to displace standing water.

Low Area
Step 1: Fill low areas with closed cell (waterproof) foam.
Foam Roof Corrects Low Area
Step 2: Apply an even layer of closed cell foam to entire roof surface.