How to choose a waterproofing system

Start with use, exposure, substrate and movement before the material name.

Residential flat roof

Modified bitumen is common; liquid membranes can be useful on roofs with many penetrations.

Large or commercial roof

TPO/PVC can work well on large areas when installers can execute and inspect heat-welded seams correctly.

Tank or bathroom

Focus on a system explicitly suitable for the intended use, with reinforced details and testing.

Thermal + waterproofing

If thermal insulation is also required, understand the complete layer build-up, UV protection and drainage rather than relying on the word “foam”.