Rubber roof paint — also sold as liquid rubber — is a flexible, rubberised waterproofing coating that cures into a seamless membrane and stretches over cracks to keep a roof watertight. It suits pitched and flat roofs, tiled and metal roofs, box gutters, valleys and parapets. Rubberised coatings such as SealFlex and SealFlex Fibre waterproof well but are not ultraviolet (UV) stable on their own, so they must be overcoated with a UV-stable topcoat — Premium Roof & Wall is the recommended choice. Modern acrylic membranes such as Shield and Fiber Coat are waterproof and UV-stable in one product. All come in 5 litre (L) and 20 L.
What rubber roof paint is
Rubber roof paint is a rubberised, elastomeric coating that cures into a continuous flexible film. The rubber content gives it high elongation, so the film bridges hairline cracks and movement joints that rigid roof paint cannot. It is applied as a thick liquid in two or more coats and dries into a seamless waterproof membrane, which is why it is also called liquid rubber. It bonds to concrete and fibre-cement tiles, corrugated iron and Inverted Box Rib (IBR) roofs, and to plaster detailing, once the surface is clean and primed.
Is rubber roof paint any good?
Yes, rubber roof paint is good for waterproofing pitched and flat roofs, gutters and parapets, because its flexible film bridges cracks and seals joints that rigid coatings split over. It handles the daily expansion and contraction of a South African roof, resists mould and abrasion, and goes on without heat or an open flame. The quality depends on three things: the binder, the film thickness, and whether it is overcoated for UV protection. A rubberised coating applied at the correct wet film thickness (WFT) over sound, primed substrate and finished with a UV-stable topcoat performs for years; the same product applied thin, over dirty substrate, or left bare in full sun fails early.
What are the disadvantages of rubber roof paint?
Rubber roof paint has four main disadvantages: it is not UV-stable on its own, it is sensitive to poor surface prep, it needs the correct film thickness, and it cannot cure standing water.
- Needs a UV topcoat. Rubberised liquid rubber chalks and hardens under ultraviolet light, so it must be overcoated with a UV-stable topcoat such as Premium Roof & Wall, or you use a UV-stable membrane instead.
- Prep-dependent. It only bonds to a clean, dry, sound surface. Dust, chalk, algae or a damp slab under the film cause peeling.
- Film thickness. Applied too thin or in a single coat, it will not reach its waterproofing WFT and leaks at the low points.
- Not a drainage fix. It seals a roof against rain but does not correct ponding water. A roof that holds water needs a fall of at least 2–4 degrees (°) first.
How long does rubber roof paint last?
Rubber roof paint lasts 5 to 8 years when overcoated for UV protection, and a UV-stable acrylic membrane lasts 10 years or more. Lifespan tracks the binder and whether the film is protected from the sun:
| Coating type | Typical life | How it is used |
|---|---|---|
| Rubberised waterproofing (SealFlex, SealFlex Fibre) | 5–8 years (overcoated) | Waterproofing layer on pitched and flat roofs, gutters and valleys — overcoat with Premium Roof & Wall |
| UV-stable acrylic membrane (Shield, Fiber Coat) | 10 years or more | All-in-one waterproof and UV-stable coat for roofs and walls |
Two coats at the correct spread rate, a clean primed surface, and a UV-stable topcoat are what carry a rubberised system to the top of that range.
What is the best paint for a rubber roof?
The best system is a rubberised waterproofing layer overcoated with a UV-stable topcoat, or a single UV-stable membrane where you want one product.
- Rubberised waterproofing + topcoat (recommended): SealFlex on sound roofs, or SealFlex Fibre where cracks are wider and need fibre reinforcement — then overcoat with Premium Roof & Wall for UV stability and colour.
- All-in-one UV-stable membrane: Shield for walls and general waterproofing, or Fiber Coat for flat and low-pitch roofs.
- Concrete or fibre-cement tiles: prime first with Roof Tile Primer, then finish with Premium Roof & Wall.
Where you can use it
Rubber roof paint works on pitched and flat roofs — concrete and fibre-cement tiles, IBR and corrugated iron, fibre-cement sheeting, box gutters, valleys and parapets. On any sun-exposed roof, overcoat the rubberised coating with a UV-stable topcoat such as Premium Roof & Wall. It does not replace a structural drainage fix on a roof that ponds water — correct the fall first.
Rubber roof paint colours
Rubberised waterproofing is usually applied in a base colour and then finished in the colour you want with the topcoat. Premium Roof & Wall carries the core roof range — grey-white, signal grey, basalt grey, anthracite grey and black — plus terracotta tones across the market. Colour affects heat: a white or light-grey roof reflects more sun and runs cooler than black or charcoal. For a dark roof that still stays cooler, a heat-reflective grade such as Heat Reflect recovers some of the loss.
Coverage: how many litres you need
Coverage depends on whether the coating is fibre-reinforced: a non-fibre rubberised coating like SealFlex covers about 6 to 8 square metres per litre (m²/L) per coat, and a fibre-reinforced coating like SealFlex Fibre covers about 3 to 4 m²/L per coat. Apply two coats, then a UV-stable topcoat. As worked examples for a 100 m² roof over two coats: the non-fibre coating needs about 25 to 33 L (roughly 1.5 of the 20 L pails), and the fibre-reinforced coating needs about 50 to 67 L (roughly 3 pails), plus the Premium Roof & Wall topcoat on top. Porous or rough surfaces pull more, so prime first. Confirm the exact spread rate on the product Technical Data Sheet (TDS).
Rubber roof paint sizes and price
Rhinoluxe rubberised coatings come in 5 L and 20 L; the 20 L pail is the economical size for a full roof. Prices move with the range and size, so the live figures for each 5 L and 20 L option sit on the product pages and the full price list. Compare on covered area, not price per pail — a fibre coating covers less per litre but bridges wider cracks, so the right choice is the one that seals your roof in two coats.
How to apply rubber roof paint (step by step)
- Clean the roof. Remove dirt, chalk and loose coating, and treat moss and lichen. The film only bonds to a clean, sound surface.
- Check the fall. Confirm a slope of at least 2–4° so water runs off. Correct ponding areas before coating.
- Prime. Prime porous concrete or frail tiles with Roof Tile Primer or a bonding liquid, and let it dry.
- First coat. Apply the rubberised coating by brush, roller or spray at the specified WFT — about 6–8 m²/L for non-fibre, 3–4 m²/L for fibre. Work it into gutters, joints and detailing.
- Second coat. Allow the first coat to dry — typically a few hours at 23 degrees Celsius (°C), longer in cold or damp weather — then apply the second coat to reach full waterproofing thickness.
- Overcoat for UV. Finish with a UV-stable topcoat such as Premium Roof & Wall, or use a UV-stable membrane like Shield or Fiber Coat from the start.
- Clean up. Wash water-based tools with water while the coating is still wet.
Rubber roof paint vs torch-on and bitumen
Rubber roof paint is a cold-applied liquid membrane, while torch-on is a bitumen sheet bonded with an open flame. Liquid rubber reaches into gutters, box ends and intricate detailing that sheets cannot wrap cleanly, needs no flame, and is easy to patch. Torch-on suits large simple flat areas. Many South African roofs use both: torch-on across the main field and a rubberised liquid at the junctions and gutters.
Frequently asked questions
Is rubber roof paint waterproof? Yes. Applied in two coats at the correct film thickness over a primed surface, it cures into a seamless waterproof membrane.
Do you have to overcoat rubber roof paint? Yes on sun-exposed roofs. Rubberised coatings are not UV-stable alone, so overcoat SealFlex or SealFlex Fibre with a UV-stable topcoat such as Premium Roof & Wall.
Can I paint over an old rubber roof coating? Yes, once it is clean, sound and dry. Remove loose material and prime any bare patches first.
What size does rubber roof paint come in? 5 L and 20 L; the 20 L is the economical size for a full roof.
Where to buy
Shop SealFlex and SealFlex Fibre with the Premium Roof & Wall topcoat, or the all-in-one Shield and Fiber Coat, with national delivery — or visit our paint shops in Table View, Cape Town and Edenvale, Johannesburg. For trade pricing on 20 L bulk orders, call +27 84 985 6141.
