Two waterproofing membrane systems dominate the South African market. Each has different strengths and suits different applications.
How torch-on membrane works
Torch-on (SBS or APP modified bitumen) membrane is a pre-manufactured sheet applied by melting the bitumen underside with a gas torch and pressing it onto the primed substrate. The result is a thick, uniform membrane that bonds completely to the surface when correctly applied. It is very durable and highly resistant to puncture and mechanical damage.
How liquid waterproofing works
Liquid-applied systems are coatings or resins applied by brush, roller or spray that cure in-place to form a seamless membrane. Because they are applied as a liquid, they conform to any shape and self-detail around penetrations, drains and upstands without cutting and overlapping sheet. The tradeoff is that membrane thickness is controlled by application rate - consistent application is critical.
Where torch-on outperforms
Large flat roof areas with few penetrations, where consistent membrane thickness and durability are priorities. Torch-on is the industry standard for flat roofs in South Africa for good reason - it is robust, long-lasting and well-understood by the trade.
Where liquid membrane outperforms
Complex shapes with multiple pipe penetrations, irregular surfaces, vertical applications on parapet walls, retrofits where torch-on cannot be applied safely near combustible substrate, and smaller areas where the mobilisation cost of torch-on equipment doesn't make sense. Liquid membranes are also used over torch-on as a maintenance coat.
Frequently Asked Questions
Which is more durable long-term in Bloemfontein's climate?
Torch-on membrane correctly applied is generally more durable - typical lifespans of 15–20 years. Quality polyurethane or cementitious liquid systems are 10–15 years. Both depend heavily on correct application.
Can liquid membrane be applied on top of failed torch-on?
Sometimes, if the existing membrane is still bonded. If the torch-on has lifted, blistered or delaminated, it needs to come off before any overlay system is applied.
Which waterproofing type do you recommend for a Bloemfontein flat roof?
For large flat roofs, torch-on is our standard recommendation. For complex retrofit situations and areas with penetrations or vertical details, liquid membrane complements or replaces torch-on depending on the specifics.
Need professional help?
Our waterproofing team covers all of Bloemfontein, 24/7.
Waterproofing in Bloemfontein