Aliphatic polyurea — outstanding UV colour and gloss stability
Waterproofing exposed concrete, cement-tile and screed roofs
Rayson SealForce RC40
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.
Best for
Best for exposed flat and pitched roofs that must stay UV-stable and reflective for decades — over concrete, screed, old membranes, metal, PU foam or bitumen.
Real product · Interactive depth view Rayson SealForce
Product system Rayson SealForce RC40
Sets (A+B) of 21 kg and 5.25 kg RY-TDS-1101
Rayson SealForce RC40 has one clearly defined, verifiable job in the coating system.
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. Best for exposed flat and pitched roofs that must stay UV-stable and reflective for decades — over concrete, screed, old membranes, metal, PU foam or bitumen.
Certified cool-roof reflectance in white (high SRI)
Cool-roof coating where solar reflectance is required
Effectively zero water uptake; excellent crack-bridging
Rooftops subject to prolonged ponding water
Waterproof the roof. Reflect the heat.
A UV-stable, walkable aliphatic polyurea membrane for exposed roofs requiring durable waterproofing and cool-roof performance.
A controlled route to applying Rayson SealForce RC40.
This sequence supports early planning. It does not replace the current Technical Data Sheet, approved method statement or project-specific technical review.
- 01
Inspect and prepare the substrate
Exposed roofs of concrete, cement tiles or cementitious screed
- 02
Prepare the material as specified
Two parts mixed 13:8 (A:B) by weight; stir Part A ~1 minute, then combine and low-speed mix ~3 minutes until homogeneous; apply undiluted in at least two layers
- 03
Apply with the correct tools
Recommended methods: Roller, Brush, Airless spray. Confirm coat count and thickness for the project.
- 04
Protect through the required cure
Touch/recoat ~18 h at 23 °C; resists early rain after 3 h; full hardening ~7 days
Coating system cutaway
Every layer has a job—from prepared substrate to service surface.
This diagram explains a typical system position, not a fixed specification. Primer, body coat, finish, thickness and detailing must be confirmed for the project.
Position in the system Standalone coating
Rayson SealForce RC40 serves as the standalone coating. Confirm the complete build-up against the substrate, exposure and project requirements.
Related system products
Review primers, body layers, finishes or specialist components connected to this product.
- Rayson SealForce RC40Standalone coating · Polyurea
- Approved primer / baseIncluded when required by the system design
- Correctly prepared substrateExposed roofs of concrete, cement tiles or cementitious screed
Four project facts for faster system screening.
These current product figures support early selection. Confirm the final build-up, quantity and application conditions against the Technical Data Sheet and site conditions.
- Coverage
- Coverage
- Mixing & working time
- Mixing
- Drying & curing
- Curing
- Pack configuration
- Pack
1–1.2 kg/m² total over two layers on cementitious surfaces
Two parts mixed 13:8 (A:B) by weight; stir Part A ~1 minute, then combine and low-speed mix ~3 minutes until homogeneous; apply undiluted in at least two layers
Touch/recoat ~18 h at 23 °C; resists early rain after 3 h; full hardening ~7 days
Sets (A+B) of 21 kg and 5.25 kg
Confirm the substrate and real service environment before specifying.
Choose it when
- Waterproofing exposed concrete, cement-tile and screed roofs
- Cool-roof coating where solar reflectance is required
- Rooftops subject to prolonged ponding water
- Recoating and protecting sound existing waterproofing membranes
- Overcoating bitumen, PVC/TPO single-ply membranes and PU-foam insulation
- Waterproofing light metal roofs
Relevant applications
Relevant industries
Choose something else when
- Apply only on a primed substrate — primer depends on the roof material
- Substrate moisture below 4%, RH below 85%, air/substrate temperature +5 °C to +35 °C
- Substrate temperature must stay at least 3 °C above dew point
- Do not apply if rain is expected during application or cure
- Keep each unreinforced layer below 1 kg/m² to avoid solvent entrapment
- Component B shelf life is shorter than Component A — check dates before use
- Application without a suitable primer
- Buried or below-grade tanking under hydrostatic pressure
- Application in wet conditions or when rain is imminent
- Trafficked vehicle decks without a dedicated wearing system
Other Rayson products to evaluate
These links continue the comparison; they are not automatic substitutes. Confirm the substrate, exposure and complete build-up before selection.
Substrate requirements+
- Exposed roofs of concrete, cement tiles or cementitious screed
- Metal roofs and surfaces (with the appropriate primer)
- Over sound bitumen membranes, PVC/TPO single-ply and old liquid membranes
- Over PU-foam insulation
- Substrate moisture below 4%, relative humidity below 85%
Technical documents and project support
Ready to specify Rayson SealForce RC40? Give Rayson the site conditions.
Send the area, substrate condition, expected traffic or exposure, required finish and programme. The technical team can help review the system build-up and estimated quantity.
What to know before specifying Rayson SealForce RC40.
Why choose an aliphatic polyurea for a roof?
Aliphatic (polyaspartic) polyurea keeps its colour and surface under ultraviolet light, where aromatic polyureas darken over time. On an exposed roof in Singapore sun, that UV stability keeps a cool-roof surface reflective and looking right for years.
Does SealForce RC40 need spray equipment?
No. Unlike hot-spray polyureas, RC40 is cold-applied by roller, brush or airless spray in at least two layers, so it suits ordinary roofing works and detail-heavy roofs without a heated plural-component rig.
Can it go over my existing roof membrane?
Yes, over sound bitumen, PVC/TPO single-ply, PU-foam insulation or old liquid membranes, each with the correct primer and after proper preparation. A failing or debonding membrane must be dealt with first.
What makes it a cool roof?
In the white shade it has a high solar reflectance and infrared emittance, reflecting sunlight instead of absorbing it. That lowers roof-surface and internal temperatures and can contribute to green-building credits.
How soon is it safe from rain?
It resists early rain about 3 hours after application, with full hardening in roughly 7 days. Timings lengthen in cool, humid conditions and shorten in heat.
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