Asmaco Anchorseal Water Stop Sealant Spray 400ml — Rubberised Waterproof Leak & Crack Sealer (Black / White / Grey / Terracotta)
A rubberised waterproof membrane in a spray can
Anchorseal Water Stop bridges leaking cracks, pinholes, seams and joints on roofs, gutters, concrete, metal and PVC — and it bonds even when the surface is wet, so you can stop a leak in the middle of the rains.
What Asmaco Anchorseal Water Stop Actually Does
Asmaco Anchorseal Water Stop is a single-component rubberised coating in a CFC-free aerosol can. Sprayed on, it cures into a continuous rubber film that bridges the crack or pinhole and flexes with the substrate instead of cracking away from it — it moves with mabati sheets in the heat and with concrete as it shrinks.
It bonds to damp and wet surfaces, so a leaking gutter or roof valley can be sealed during the rains without waiting for it to dry.
The cured film is non-fading and non-yellowing, so a White or Terracotta repair keeps its colour. On metal it does double duty: it seals the leak while sealing out water and oxygen, arresting the corrosion that caused the pinhole — a practical fix for rusted IT4/IT5 sheets, galvanised gutters, tank seams and drip pans.
Manufacturer: Anchor Allied Factory LLC (UAE),Item code: ASWS400.
Six Reasons Contractors Keep a Can on the Van
Seals on Wet or Dry Surfaces
Bonds to damp substrates, so an active leak can be stopped during the rains without waiting for the roof or gutter to dry out.
Permanently Flexible Film
The cured rubber film stretches and recovers with substrate movement — it will not crack on cold nights or go brittle under roof heat.
Weather & Colour Stable
Non-fading and non-yellowing. Resists rain, sun and temperature swings without chalking, blistering or peeling back.
Stops Corrosion at Source
Encapsulates bare and rusted metal, cutting off water and oxygen so the pinhole does not simply reopen next season.
Non-Sag, Non-Drip Build
Holds on vertical and overhead surfaces and builds thickness without running, leaving a semi-smooth semi-gloss finish.
Damps Noise & Vibration
The rubberised layer deadens drumming on metal sheets, ducting and panels — a useful side benefit on mabati roofs.
Full Technical Data
Figures follow the manufacturer's technical data sheet for Anchorseal Water Stop aerosol sealant.
| Property | Value |
|---|---|
| Product type | One-component rubberised protective coating and leak sealer, aerosol applied |
| Brand / line | Asmaco — Anchorseal (Anchor Allied Factory LLC, UAE) |
| Item code | ASWS400 (400 ml) |
| Propellant | Liquefied petroleum gas, CFC-free (ozone friendly) |
| Non-volatile matter | 40 ± 5 % |
| Specific gravity | 0.995 ± 0.08 |
| Finish | Semi-gloss, semi-smooth, flexible hard film |
| Colours available | Black, White, Grey, Terracotta |
| Surface dry | 20 – 30 minutes |
| Hard dry | 45 – 60 minutes |
| Recoat with itself | After 20 – 30 minutes |
| Over-coating with paint | After 24 hours (test compatibility first) |
| Application temperature | 10 °C – 32 °C |
| Max substrate temperature | Do not spray onto surfaces hotter than 93 °C |
| Spray distance | 8 – 18 cm from the surface |
| Substrate condition | Applies to wet or dry surfaces |
| Key performance | Waterproof, anti-corrosive, flexible, non-fading, non-yellowing, non-sag, weather and UV resistant, sound and vibration damping |
| Suitable substrates | Concrete, masonry and plaster, galvanised iron and mabati sheets, mild steel, aluminium, PVC and uPVC pipe, fibreglass, timber, bitumen felt, ducting and most rigid plastics |
| Packaging | 400 ml can — 12 per carton; 100 ml can — 24 per carton |
| Shelf life | 24 months from manufacture, unopened |
| Storage | Cool, dry, shaded store below 50 °C, away from sunlight and ignition sources |
Typical manufacturer figures at 25 °C and 50% RH. Drying times lengthen in cold, humid or poorly ventilated conditions and on heavy build coats.
Four Colours — Match the Repair to the Surface
Typical Applications in Kenyan Building Work
Application Guide — Step by Step
Allow roughly an hour from first spray to hard dry. Work in shade where possible and never spray in direct midday sun on a hot metal roof.
Prepare the surface
Scrape off loose or flaking paint, rust scale, moss and dirt. Degrease oily patches. Lightly sand glossy or previously painted surfaces to give the coating a key. The surface may be damp, but it must be sound and free of standing water.
Mask surrounding areas
Overspray cures into a permanent rubber film, so mask adjacent tiles, glass, paintwork and fittings. Work with good ventilation and keep the can away from flames, sparks and hot surfaces.
Shake the can properly
Shake vigorously for at least one minute until the mixing ball rattles freely, and keep shaking briefly every 20–30 seconds during use. Under-shaken cans spray thin and give patchy colour.
Lay a light mist coat
Hold the can upright, 8–18 cm from the surface, and apply a thin first pass in overlapping strokes. This tack coat anchors the build coats that follow. Leave 20–30 minutes.
Build the seal in thick coats
Apply heavier coats at 20–30 minute intervals, extending 3–5 cm beyond the crack or hole on every side, until the defect is completely bridged. Two to four coats is typical for a pinhole.
Cure, inspect, top coat
Hard dry takes 45–60 minutes. Inspect for thin spots once dry and spot-coat as needed. If the repair is to be painted, wait a full 24 hours and test the top coat on a small area first.
Read Before You Spray
⚠ Handling & Storage
- Pressurised, flammable container. Keep away from open flames, sparks, hot surfaces and welding.
- Do not pierce, crush or burn the can, even when empty.
- Never store above 50 °C or in direct sunlight — cans may burst.
- Do not spray onto surfaces hotter than 93 °C.
- Use in a well-ventilated area; avoid breathing the spray mist. Wear gloves and eye protection.
- Keep out of reach of children. Do not spray towards people, animals or live electrical gear.
ⓘ Practical Limits
- Apply between 10 °C and 32 °C for proper film formation.
- It bridges cracks, pinholes and seams — it is not a structural repair or a substitute for a full roof membrane on a failed roof.
- Wide or moving cracks should be backed with tape or mesh before over-spraying.
- Not for internal potable water tank linings or food contact surfaces.
- Not designed for permanent immersion under pressure.
- Shabbiri Hardware supplies material only; we can share contacts of independent applicators.
Frequently Asked Questions
Can it be sprayed on a wet surface?
Yes. Anchorseal Water Stop is formulated to bond to damp and wet substrates, so an actively leaking gutter, roof sheet or water tank can be sealed during the rains without waiting for the surface to dry. Clear standing water and loose debris first, then spray.
What colours does it come in?
Four: Black, White, Grey and Terracotta. Terracotta for clay-tile roofs and chimneys, White for gutters, fascia and PVC downpipes, Grey for concrete, plaster and galvanised steel, Black for bitumen felt and dark mabati.
How long does it take to dry?
Surface dry in 20–30 minutes and hard dry in 45–60 minutes at normal Nairobi temperatures. Recoat with itself after 20–30 minutes, but wait a full 24 hours before applying paint or any other top coat.
Can I paint over it?
Yes. Let the film cure for 24 hours, then apply a compatible water-based or solvent-based paint. Because the cured surface is a flexible rubber film, always test your top coat on a small area first.
How many cans will I need?
A 400 ml can typically covers a hairline crack run of several metres, or a patch of roughly 0.5–1 m² at full build thickness. For long gutter runs or a large corroded area, budget two to three cans per 5 metres and buy the 12-can carton.
Is it the same as a liquid waterproofing membrane?
No. Anchorseal Water Stop is a targeted repair sealer for cracks, pinholes, joints and seams. For waterproofing a whole slab, bathroom or roof area, a brush- or roller-applied system such as SikaTop-590 Seal is the right product — we stock those too and can advise which fits your job.
Where can I buy Asmaco Anchorseal in Nairobi?
At Shabbiri Hardware, both branches on Magadi Road — Ongata Rongai (opposite Hashi Petrol Station) and Tuala (past Nazarene University). Call 0741 042484 or 0745 554008, WhatsApp us, or email info@shabbirihardware.com. Single cans or full 12-can cartons, with delivery around Nairobi and Kajiado.
Buy Asmaco Anchorseal at Either Branch
Both branches sit on Magadi Road and carry the full Asmaco range alongside Sika and Akfix construction chemicals.
📍 Ongata Rongai Branch
Magadi Road, Ongata Rongai — opposite Hashi Petrol Station, Nairobi, Kenya.
Phone: 0741 042484
Need Asmaco Anchorseal Water Stop Today?
Tell us the colour and quantity and we will send a quotation right away. Single cans or full 12-can cartons, ready at both Magadi Road branches.
Specifications
| Brand | Asmaco |
| Model | ASWS400 |
| Category | Silicone Sealants & Fillers |
| Availability | In stock |
| Sourced by | Shabbiri Hardware Kenya Limited |
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