What Is Torch-On Waterproofing & Why Is It the Best System for Flat Roofs?
Torch-on waterproofing involves the heat-bonding of an SBS-modified bitumen membrane to a prepared surface using a gas blowtorch. Once applied, the membrane creates a continuous, tough and elastic barrier that is completely impermeable to water — making it the industry gold standard for flat and low-slope roof applications.
Unlike cold-applied liquid coatings, a torch-on membrane is physically fused to the substrate. There are no seams, no joints and no areas of weakness. The result is a roof surface that flexes with thermal movement, resists UV degradation and can last over a decade with minimal maintenance.
RR Roof Waterproofing has installed torch-on systems on residential garages, commercial rooftops and large industrial slabs across Centurion and Gauteng for over 15 years. Every installation begins with a thorough surface assessment and ends with a written 10-year guarantee.
5 Reasons Torch-On Is the
Superior Waterproofing System
Highly Durable
An SBS-modified bitumen membrane lasts over a decade under South Africa's harsh UV and thermal cycling conditions — far outlasting most painted or liquid-applied alternatives.
100% Seamless Barrier
The heat-bonding process fuses the membrane directly to the substrate, eliminating cold joints and seams. There is no weak point for water to penetrate — even under standing water.
Structural Flexibility
SBS-modified bitumen remains elastic even at low temperatures, allowing the membrane to expand and contract with the building structure without cracking or delaminating.
UV & Heat Resistant
Mineral-surfaced torch-on membranes reflect solar radiation and resist UV degradation. This reduces heat build-up under the membrane and extends service life significantly.
10-Year Written Guarantee
Every torch-on installation we complete is backed by a written 10-year guarantee. You receive documented protection, not just a verbal promise — providing peace of mind for a decade.
Before & After
Drag the slider handle to reveal the transformation. Real project, real results — no filters.
Torch-On membrane waterproofing — flat roof, Centurion
Torch-On Waterproofing for
Every Property Type
Home Torch-On Waterproofing
Torch-on is ideal for homes with flat concrete roof sections, garage slabs, balconies or roof-top patios. It provides a permanent solution to persistent leaks — far more reliable than painted or brush-applied coatings.
Most residential jobs are completed within a single day with minimal disruption to your household.
Commercial Torch-On Waterproofing
Office parks, retail centres, schools and mixed-use buildings often feature large flat concrete roof areas that are vulnerable to water ponding and joint failure. We install robust torch-on systems designed to handle foot traffic, mechanical installations and Gauteng's intense summer rainfall.
We schedule around your operations — including after hours and weekends — to keep your business running throughout.
Industrial Torch-On Waterproofing
Factories, warehouses and logistics facilities endure some of the harshest roof conditions — vast surface areas, high thermal movement, chemical exposure and constant foot traffic. Torch-on is the best defence against these demands.
Our industrial-grade torch-on installations include reinforced detailing at all joints, drains and penetrations — the areas most prone to failure.
Our Torch-On Application Process
A torch-on membrane is only as good as the surface it's applied to. Our process prioritises surface preparation above everything else — because poor prep is the single biggest cause of early membrane failure.
Roof Inspection & Quotation
We assess the slab, surface condition, pitch, drainage layout and any previous waterproofing. You receive a written condition report and itemised quotation before any work begins.
Surface Preparation
All loose material, old failed membrane and contamination is removed. Cracks and spalls are repaired with appropriate patching compound to create a clean, sound substrate.
Bitumen Primer Application
A bituminous primer is applied to the prepared surface to improve adhesion and penetrate any residual moisture. We do not apply the membrane until the primer has fully cured.
Detail Waterproofing First
All corners, upstands, pipe penetrations, drainage outlets and parapet junctions are treated first with reinforcing mesh and membrane — the areas most vulnerable to leaks are sealed before the field.
Torch-On Membrane Application
Using high-heat gas torches, we lay the SBS-modified bitumen membrane across the full roof surface with correct overlaps, ensuring a seamless continuous barrier with no cold joints.
Final Inspection & Guarantee
We conduct a final inspection of all seams, overlaps and detailing. Where possible, a water test is performed. A written 10-year guarantee certificate is issued on completion.
Torch-On Done Right,
Backed by a 10-Year Guarantee
We use SABS-approved SBS-modified bitumen membranes matched to your roof's specific requirements. A mismatch between membrane grade and substrate is the primary cause of early waterproofing failure — we never compromise on product selection or surface preparation.
"Herman and his team did an excellent job re-sealing our concrete roof. Herman also kept us informed on a continuous basis regarding the exact starting date and time which is highly appreciated."
Frequently Asked Questions About Torch-On Waterproofing
A professionally installed torch-on SBS-modified bitumen membrane carries a 10-year written guarantee with us. With regular maintenance inspections every 3 years — checking seams, outlets and parapet flashings — the system can comfortably last 15 years or more.
Torch-on membranes are ideal for flat or low-slope concrete roofs, garage slabs, balconies, parapet walls, boundary walls, terraces and roof decks. The surface must be structurally sound, clean and primed before application. We do not apply torch-on over loose, contaminated or wet surfaces.
Yes — torch-on is an excellent choice for residential homes with flat concrete roof sections, garages, balconies or roof-top patios. It provides a permanent, durable solution that outperforms painted or brush-applied waterproofing coatings significantly. Most residential jobs are completed within a single day.
No. The surface must be completely dry before we apply primer or membrane. Moisture trapped under a torch-on membrane causes blistering and premature failure. We schedule our jobs around the weather forecast and will never apply a membrane on a damp surface — even if it means rescheduling.
Torch-on uses a heat-applied SBS-modified bitumen membrane for maximum durability and longevity — the preferred system for any flat roof or large slab. Liquid waterproofing is a cold-applied coating better suited to complex shapes, penetrations and areas where open flame is not permitted. We recommend torch-on for any application where it is practicable.