Do You Need Primer for Polyurethane Waterproofing? Ghana 2026
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Yes — on most Ghanaian concrete you need a primer before polyurethane waterproofing. Primer binds dust, seals pores against pinholes and gives the membrane something to grip. It is not one of the two membrane coats. Near the coast, a chloride-blocking primer is one of the two upgrades that lift realistic service life toward the full 20-year design life.
What primer actually does
- Binds the surface. Concrete has a weak, dusty top layer called laitance. Harmattan adds more dust. A coating applied on that layer is bonded to dust, not concrete.
- Seals pores. Porous concrete releases air as it warms in the sun. Without primer, that air bubbles through the wet coating and leaves pinholes.
- Improves adhesion. Peel failures nearly always trace back to preparation, not product.
- Blocks salts (coastal primer). Within 15 km of the sea, chlorides on the surface can undermine the bond over time.
When primer matters most
| Surface | Primer need | Why |
|---|---|---|
| New concrete slab | High | Laitance and open pores |
| Old weathered slab | High | Dust, friable surface, old coating residue |
| Sand-cement screed | High | Very porous |
| Coastal roof (<15 km) | High — chloride-blocking | Salt deposits |
| Over existing sound PU | Product-specific | Clean and abrade; follow manufacturer guidance |
Coastal service life: where primer pays
Design life is always 20 years. Realistic outcomes vary by location:
- Inland (Kumasi, Koforidua, Bolgatanga, Wa, Tamale): 18-20 years
- Coastal within 15 km (Accra, Tema, Takoradi, Winneba, Cape Coast): 14-17 years standard; 17-20 years with coastal-rated fleece plus a chloride-blocking primer
That is the honest case for spending more near the sea. Inland, a standard primer is enough.
Primer is not a substitute for preparation
Primer goes on a surface that has already been cleaned, dried, and had its cracks opened and filled. It will not fix a wet slab (see can you waterproof a wet roof), and it will not hold down old coating that is already lifting — that must be stripped.
Don't count it as a coat
Some quotes list "primer + 1 coat" and call it a two-coat system. It isn't. Waterproofing requires two full membrane coats on top of primer, and one coat is not waterproofing — it pinholes and fails in the first heavy rains. Ask any contractor how many kilograms of membrane their price includes, separately from primer. Our working rate is 1 kg per m² across two membrane coats — verified on our Amasaman concrete gutter and floor slab job, 130 m² with 13 × 10kg buckets, exactly 1.0 kg per m². See the job on video.
Membrane quantities
- Polyurethane Coating 5kg — GHS 500: 10 m² on one coat → 5 m² finished (2 coats)
- Polyurethane Coating 10kg — GHS 1,000: 20 m² on one coat → 10 m² finished (2 coats)
Primer is quoted and bought separately. It does not reduce the membrane quantity you need.
Warranty
Fest Ghana installations carry a 3-year workmanship warranty plus a 3-year manufacturer material warranty. The warranty is the period we return and fix it at our cost. The design life — 20 years — is how long the membrane is engineered to keep performing.
Book an inspection
Book online or call 0555 548 001.
Related Resources
- Why waterproof coating peels off
- How to apply polyurethane coating
- Coastal salt protection
- How many coats of polyurethane?
- Waterproofing over old paint or coating
Fest Ghana Limited is the trading name of FGL Waterproofing Solution Limited Company, a company registered in Ghana — Registration No. CS218171026. Company information.