Polyurethane — The Complete Guide for Ghana (2026)
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Polyurethane — The Complete Guide for Ghana
Polyurethane is a synthetic polymer made by reacting a polyol with a diisocyanate. Depending on how it is formulated it becomes a flexible waterproof membrane, a rigid insulating foam, a tough coating, a sealant, or an adhesive. In Ghanaian construction, the dominant form is single-component polyurethane liquid membrane — the system Fest Ghana Limited uses for roof, parapet, gutter, tank, and balcony waterproofing.
How Polyurethane Actually Works
Liquid polyurethane is applied wet, like a thick paint. As it cures it reacts with atmospheric moisture and cross-links into a single continuous rubber sheet with no joints or seams.
That seamlessness is the whole point. Sheet membranes leak at overlaps. Tiles leak at grout lines. Paint cracks. A cured polyurethane membrane has nothing to leak through — it is one unbroken skin bonded directly to the substrate.
The Types of Polyurethane You'll Meet in Ghana
| Type | Form | Used For |
|---|---|---|
| Liquid membrane (1-component) | Brush/roller applied | Roof, parapet, gutter, balcony waterproofing |
| Liquid membrane (2-component) | Mixed on site | Heavy-duty decks, car parks, plant rooms |
| Spray foam (SPF) | Machine sprayed, expands | Thermal insulation, cold rooms, ductwork |
| Sealant | Cartridge/gun applied | Joints, penetrations, window perimeters |
| Floor coating | Roller/squeegee | Warehouses, workshops, industrial floors |
| Injection resin | Pressure injected | Structural crack repair, water-stopping |
Important distinction: polyurethane liquid membrane stops water. Polyurethane spray foam stops heat. Same chemical family, completely different products, completely different equipment. Do not let a supplier substitute one for the other.
Why Polyurethane Suits Ghana Specifically
Ghana punishes building materials in ways temperate climates do not:
| Ghana Condition | Kills | Polyurethane Response |
|---|---|---|
| Roof surface to 75°C | Bitumen (softens at 55°C) | Stable to 80°C+ |
| UV index 11+ year-round | Bitumen, cheap acrylics | UV-stabilised formulation |
| 20°C daily thermal swing | Rigid cement systems | 200%+ elongation, moves with slab |
| 100 mm/hr storm intensity | Anything with seams | Seamless, no overlaps to fail |
| Coastal salt within 15 km | Untreated concrete | Chloride barrier with primer |
| Harmattan drying to 15% RH | Brittle coatings | Stays elastic, bridges shrinkage cracks |
Polyurethane vs the Alternatives
| System | Elongation | Heat Limit | Design life |
|---|---|---|---|
| Polyurethane | 200%+ | 80°C+ | 20 yrs |
| Torch-on bitumen | ~40% | 55°C | 12-18 yrs |
| Cementitious slurry | <5% | High | 8-12 yrs |
| Acrylic "waterproof paint" | ~10% | Low | 2-3 yrs |
The elongation column is the one that matters. Ghanaian concrete moves every single day. A material that cannot stretch will crack — it is only a question of how soon.
What Polyurethane Costs in Ghana (2026)
| Product | Price | 1 coat | 2 coats (waterproofing) |
|---|---|---|---|
| PU Coating 5kg | GHS 500 | 20-40 m² | 10-20 m² |
| PU Coating 10kg | GHS 1,000 | 40-80 m² | 20-40 m² |
| Professional install (2-coat) | GHS 80-130 / m² | Incl. labour, prep, 3-yr warranty | |
| Professional install (fleece-reinforced) | GHS 180-280 / m² | For parapets, gutters, details | |
Coverage is quoted per coat. Waterproofing needs two.
Halve the headline figure before you order. Budget roughly 0.4 kg per m² for a finished two-coat system — a rate verified on a documented 370 m² project where 150 kg was applied. A 100 m² roof needs about 40 kg, or four 10kg buckets. Rough, old or never-sealed concrete drinks more.
How to Apply Polyurethane Correctly
- Prepare — wire-brush the surface, remove all dust, laitance, and failed old coating
- Check moisture — substrate must be below 4% moisture content
- Calculate quantity — roughly 0.4 kg/m² across two coats, and have it all on site before you start
- Reinforce details — fleece banding at parapets, drains, penetrations, and joints
- First coat — roller or brush, working in one direction, completed in one continuous session
- Cure 4-6 hours — until touch-dry
- Second coat — applied perpendicular to the first, eliminating pinholes
- Full cure 24-48 hours — no rain, no foot traffic
- Flood test — verify watertightness before handover
Steps 3 and 7 are the ones most jobs get wrong. Running short of material mid-coat leaves a cold joint, and two perpendicular coats are not the same as one thick coat — the difference shows up as pinhole leaks within a year.
Where Polyurethane Is Used on a Ghanaian Building
- ✅ Concrete flat roofs and roof slabs
- ✅ Parapet walls and roof-edge upstands
- ✅ Concrete and metal box gutters
- ✅ Balconies and terraces
- ✅ Bathrooms and wet areas (under tiles)
- ✅ Water tanks and reservoirs (potable-certified grade only)
- ✅ Swimming pools and fish ponds
- ✅ Foundations, basements, and retaining walls
- ✅ Sump pits and plant rooms
- ✅ Industrial and warehouse floors
Common Myths
"Polyurethane is just expensive paint." No. Paint is a decorative film. Polyurethane liquid membrane is an engineered elastomeric barrier with defined tensile strength, elongation, and design life. Different category entirely.
"One thick coat is faster and just as good." No. Thick coats cure unevenly and pinhole. Two coats, perpendicular, every time — which also means buying twice the material.
"You can apply it over a wet roof to stop the leak now." No. Applying to a damp substrate traps vapour and causes blistering within a year. Stop the active leak with Plugging King, let it dry, then waterproof properly.
"All polyurethane is the same." No. Grades vary in solids content, UV stabilisation, and elongation. Ask for the technical datasheet and GSA certification.
"It comes with a 20-year guarantee." No. 20 years is the design life — what the membrane is engineered to deliver when installed correctly and maintained. The warranty is 3 years workmanship and 3 years manufacturer material. Anyone in Ghana offering a 20-year warranty on waterproofing is quoting design life under the wrong heading.
Buy or Book
Fest Ghana Limited both supplies GSA-certified polyurethane products and installs complete systems with a 3-year workmanship warranty and a 3-year manufacturer material warranty.
👉 Book Free Site Assessment · Call/WhatsApp: 0555 548 001