Roof leak repair in Johor Bahru: the cause traced first, then a Rayson SealForce membrane over the whole roof by an authorised applicator. Quoted per sq ft.
We reply within one working day, Monday to Friday.
Also in Kuala Lumpur and the Klang Valley, and Penang, through authorised applicators there.
Roof waterproofing is a continuous membrane over the whole roof that keeps rain out of the roof and the rooms below. In Johor Bahru the Rayson-authorised applicator uses SealForce AC10 acrylic on roofs that drain freely, or SealForce RC40 polyurea on exposed flat roofs that pond or are walked on.
A single failed detail, such as an outlet or a pipe, can be repaired on its own. Where the membrane itself has aged and cracked, patches only move the leak, so the lasting repair is a membrane over the whole roof.
The applicator traces the stain to the entry point first and tells you which it is. Outlets, upstands and parapets are reinforced before the field coat either way.
A pitched or tiled roof that drains freely, or a roof with many penetrations: SealForce AC10 acrylic over AP05 primer. An exposed flat concrete roof that holds water or that you walk on: SealForce RC40 polyurea, UV-stable and walkable.
If water still stands on the roof a day after rain, it is an RC40 roof. AC10 is not made for ponding water or foot traffic; RC40 takes both and stays elastic through the daily heat.
Over a sound, well-bonded one, yes, after cleaning and priming. A loose, blistered or crumbling membrane is removed first, because a new coat is only as good as what it sticks to.
The applicator checks the old membrane’s bond at the inspection. Where it holds, keeping it saves the cost of stripping; where it lifts, it comes off before anything else.
Heavy, wind-driven rain reaches places light rain does not: laps, parapet tops, flashings and blocked outlets that overflow onto the roof. A leak that shows only in storms usually points to a detail rather than the whole membrane.
Tell the applicator when the stain grows and which way the wind was blowing; it narrows the search to the side of the roof that takes the weather.
| Compared on | SealForce AC10 acrylic | SealForce RC40 polyurea | Ordinary roof paint | Sealant on the crack |
|---|---|---|---|---|
| What it is | An acrylic membrane built up in coats | A polyurea membrane, UV-stable | A thin paint film | A bead over one crack or joint |
| Roofs it suits | Pitched, tiled and sound flat roofs that drain freely | Exposed flat roofs that pond or carry foot traffic | A sound roof that needs a fresh colour | One crack, as a stop-gap |
| Water standing after rain | No: fix the falls, or use RC40 | Yes | Not made for it | Not made for it |
| Walked on | No | Yes | Not made for it | Not made for it |
| Outlets, parapets and pipes | Reinforced before the membrane | Reinforced before the membrane | Painted over | Only the spot treated |
A first guide. The applicator confirms the right membrane for your roof on site.
Water travels. The applicator traces the stain to the entry point before anything is opened.
Clean to a sound substrate, repair cracks and prime to the membrane’s data sheet (SealForce AP05 under AC10 on concrete and tiles), then reinforce the outlets, upstands and parapets first.
AC10 acrylic or RC40 polyurea applied at the data sheet thickness, field coat last.
The roof takes water without a mark below before the job is signed off.
Per square foot, quoted after inspection. Five things decide it: the roof area; the membrane, where AC10 acrylic on a sound, clean roof is the lowest cost and RC40 polyurea on an exposed flat roof costs more and lasts longer; crack repair and surface preparation, priced separately; the outlets, upstands and penetrations to detail; and whether the old membrane stays or comes off. Rayson publishes no price list.
Also in Kuala Lumpur and the Klang Valley, and Penang, through Rayson-authorised applicators there; availability confirmed per enquiry.
The build-up, top to bottom · diagram, not to scale
Flat roofs that pond or are walked on: SealForce RC40 polyurea.
Rayson SealForce AC10 is a one-part, water-based acrylic waterproofing membrane for exposed roofs, old roof tiles and external walls — applied cold, straight from the pail, by brush, roller or airless spray, and drying to a seamless, elastic, UV-resistant film.
Specifications →
Rayson SealForce AP05 is a one-part, water-based acrylic primer for the SealForce waterproofing range — brushed or rolled onto concrete, render, brick, stone and roof tiles to seal pores, bind dust and give SealForce AC10 a firm surface to bond to.
Specifications →
Rayson SealForce RC40 is a two-component, cold-applied aliphatic polyurea waterproofing membrane for exposed roofs — roller-, brush- or spray-applied, UV-stable and walkable, with certified cool-roof reflectance.
Specifications →The system is specified by the company that makes the material, and installed by an independent applicator Rayson has authorised, not chosen from whatever a supplier had on the shelf that week.
Every Rayson material on your floor or roof has a published technical data sheet. You can read what went in, and so can your consultant.
Rayson warrants the material as its maker. The authorised applicator, an independent company that contracts with you, warrants the workmanship. Each warranty is issued by the company responsible for it.
The products, data sheets and application methods are the ones Rayson publishes in Singapore. Nothing is rebadged for Malaysia.
Contractors and facility teams buy the same materials direct from the maker, with application guidance. The applicator is there when you want the job done for you.
Each with the Rayson layers it uses
All jobs in Johor ↗Read the stain first: toilet above, roof, pipe or wall each need a different repair.
Under a roof: a roof membrane instead. A steady drip in any weather: a plumber first.
Quoted after inspectionLarge flat and metal roofs in Johor’s industrial parks, coated without stopping production.
Metal and free-draining roofs: SealForce AC10, over an anti-corrosion primer on metal or AP05 on concrete.
Quoted after inspectionSurfaces that are rained on and walked on, with a room underneath that must stay dry.
Under new tiles: SealForce WB20 beneath a protected screed.
Quoted after inspectionA terrace-house roof typically takes two to four dry days: preparation and details on the first day, coats on the following days, then a rain check. The quotation states the programme.
Yes, between the rains. Each coat needs a dry surface and dry hours to cure, so the applicator plans the work days around the forecast.
Two warranties, two companies: Rayson warrants the membrane as its maker, and the Rayson-authorised applicator warrants its workmanship. Both are written into the quotation.
Tell us what the surface is, where it is and what it has to withstand. Rayson replies with a system recommendation; for installation, the applicator for your area in Johor, Kuala Lumpur or Penang is introduced to quote the job.
Malaysia launch: 1 March 2027. Enquiries are welcome now; supply, site assessment and installation timing are confirmed for each project.