Why Your New-Build Roof Is Already Leaking in Ghana (Contractor Mistakes to Avoid)
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Why Your New-Build Roof Is Already Leaking in Ghana
You just moved into your brand-new home in Accra. The first heavy rain arrives. Water starts dripping from the ceiling. You feel betrayed — you paid full price for new construction, and it's already failing.
You're not alone. In Ghana, an estimated 30–50% of new-build residential homes experience roof leakage within their first two rainy seasons. The problem is almost never the material — it's the installation. This guide covers the 7 most common contractor mistakes that cause new-build leaks and what you can do about them.
Why New Homes Leak (When They Shouldn't)
The uncomfortable truth: many Ghanaian building contractors cut corners on waterproofing because:
- Waterproofing is 1.5–4% of build cost — easy to underbid and skip
- The homeowner rarely inspects during application
- The defect only appears months later (during rainy season)
- By then the contractor has moved on and won't respond
Here are the 7 mistakes that cause 90% of new-build leaks:
Mistake #1 — Waterproofing Skipped Entirely
Some contractors don't waterproof concrete roofs at all. They rely on "waterproof paint" — which is decorative paint, not waterproofing. This lasts one rainy season, if that.
How to spot it: Ask for waterproofing product invoice/receipt. If contractor can't produce it, waterproofing likely wasn't done.
Fix: Full professional polyurethane liquid membrane application. See: How to Waterproof Your Roof Before Rainy Season.
Mistake #2 — Wrong System Used (Waterproof Paint Instead of Membrane)
Contractor applied waterproof PAINT (0.05 mm thin decorative film) instead of waterproof COATING (0.8–1.2 mm elastic membrane). These are NOT the same thing.
Reference: Waterproof Paint vs Waterproof Coating.
Fix: Strip failed paint and apply proper polyurethane liquid membrane.
Mistake #3 — Single Coat Instead of Two
Polyurethane waterproofing requires TWO coats applied perpendicular to each other. One coat = pinholes = leaks within 6 months.
How to spot it: Look for consistent membrane thickness. Thin/patchy areas indicate single-coat application.
Mistake #4 — No Fleece Reinforcement at Corners
Internal corners, drainage outlets, pipe penetrations, and parapet upstands need fleece reinforcement embedded in the first coat. Without it, thermal cycling cracks the membrane at these exact points within 12 months.
Mistake #5 — Parapet Upstand Too Low
Parapet waterproofing needs a minimum 150 mm upstand height above finished roof level (200 mm preferred for Ghana's heavy rain). Contractor often does 50–100 mm to save material — storms wash water over the top.
Reference: Parapet Wall & Roof Edge Waterproofing.
Mistake #6 — Waterproofing Applied Over Wet Substrate
Concrete must be fully dry (below 4% moisture) before waterproofing application. Contractors under time pressure often skip this drying period, apply over damp concrete, and the membrane won't bond. Fails within months.
Mistake #7 — Drainage Under-Sized or Wrongly Placed
Ghana's rainfall can exceed 100 mm/hour in peak storms. Roof drainage sized for UK/European standards (75 mm/hour) will pond. Ponding water damages membranes and causes localized failure.
What to Do If Your New-Build Is Leaking
Step 1: Document Everything
- Photos of every damp patch, ceiling stain, wall damage
- Video during rain showing active water penetration
- Dates of each observation
- Copy of original contract with waterproofing specification
Step 2: Notify Contractor in Writing
Send WhatsApp + email with photos + demand for site inspection within 7 days. Keep all correspondence.
Step 3: Get Independent Assessment
Have Fest Ghana Limited or another qualified waterproofing specialist inspect. They will identify the specific mistake(s) and quote proper repair.
Step 4: Enforce Defects Liability Period
If you're within your Defects Liability Period (usually 12 months), contractor is legally obligated to fix at their cost. Send formal notice via lawyer if they refuse.
Step 5: Fix It Properly Yourself If Contractor Won't Comply
If contractor refuses or has disappeared, hire a proper waterproofing specialist. Keep receipts — you may still be able to recover costs later.
Preventing This Problem (For Anyone Building)
- Insist on written waterproofing specification in contract (product, thickness, coverage, warranty)
- Require warranty transfer from waterproofing sub-contractor to you
- Attend site during application — or send someone knowledgeable
- Get flood test certification — verified before handover
- Retain 10% payment until first rainy season passes without leaks
- Reference: Warranty & Insurance Guide
Cost to Fix New-Build Waterproofing Failure
- Full roof strip + reapplication: GHS 15,000–40,000
- Spot repair (single failure area): GHS 3,000–10,000
- Parapet-only re-do: GHS 5,000–15,000
- Comprehensive envelope re-do (roof + walls): GHS 25,000–60,000
Book a Free New-Build Assessment
If your new home is leaking, Fest Ghana Limited will inspect and provide a written report you can use to hold your original contractor accountable — or fix the problem properly ourselves.
👉 Book Free Assessment · Call/WhatsApp: 0555 548 001