Walk into a shop and ask for roof paint and you may be offered any of three quite different things. They cost different amounts, they do different jobs, and only one of them addresses a leak. Sorting them out before you buy saves a season of disappointment.
The three products
Roof paint
A decorative or reflective coating for a roof surface. Its purposes are appearance and, in the case of light-coloured "cool roof" products, reducing how much heat the roof absorbs. It is a paint film on a roof.
What it does not do: stop water getting into a slab. A paint film has neither the thickness, the flexibility nor the crack-bridging behaviour to act as a barrier, and it will not survive standing water.
Roof coating
The vague middle term, and the one to be most careful with. It covers everything from a thick elastomeric membrane down to an exterior emulsion described as "with waterproofing properties". The words on the tin will not tell you which end of that range you are holding.
What to ask: is this a barrier system or a paint that resists water? The answer determines whether it can be expected to stop a leak.
Roof waterproofing
A system, not a tin. Preparation, crack repair, junction and detail treatment, the barrier itself applied at a specified thickness in a specified number of coats, proper cure, and a water test. The material is one component of it. The full sequence.
Which do you need?
Your roof leaks, or the ceiling below shows damp. Waterproofing, done as a system. No paint and no coating will fix this, and money spent on one is money spent twice. Start at why roofs leak to find out what is actually wrong.
Your roof is sound but the top floor is unbearably hot. A reflective roof paint is a reasonable purchase — provided the roof genuinely is sound. Be careful with performance claims: any specific temperature reduction depends on your roof construction, your climate and what else is on the roof, and a figure quoted without those conditions is marketing rather than information.
Your roof is sound and you want it to look better. Roof paint. Fine.
Your roof is sound and you want to keep it that way. This is the good case and the cheapest moment to act. Preventive waterproofing before problems appear, timed for the dry season — before the monsoon, working from the pre-monsoon checklist.
Two things that decide the outcome more than the product
Standing water
If water stands on your roof after rain, no product on this page will hold for long. The falls are wrong, and falls are corrected with screed and drainage, not chemistry. Pour a bucket out and watch where it goes; anything still pooling an hour later is a drainage problem.
The edges
Roofs leak at junctions far more than in the middle — the parapet base, the drain outlets, pipe penetrations, the expansion joint. A treatment rolled across the open area and stopped at the corners has left the actual leak untreated. See parapet junctions.
Claims that should end the conversation
- "One coat, permanent solution." Nothing on a roof is permanent, and one coat is rarely the specified thickness.
- "It can be applied in the rain / on a damp surface." Almost nothing bonds properly to a wet substrate.
- "This paint will stop your leak." It will not.
- A specific temperature or lifespan figure offered without asking anything about your roof.
Related reading
Not sure which of the three your roof needs? Send photographs and tell us what happens after rain — that is usually enough for us to tell you, including when the answer is that you do not need to buy anything from us yet.