Site Engineer's Waterproofing Checklist for Construction

Q: When should waterproofing be inspected during construction?

Before it gets covered up. Membrane on a roof needs sign-off before screed or tiling goes over it; bathroom waterproofing needs inspection before tiling; below-grade waterproofing needs sign-off before backfilling. Once covered, defects are expensive to trace and fix.

Q: What is the single most common construction-phase waterproofing mistake in Ghana?

Applying membrane over a substrate that hasn't been properly prepared or cured, and covering it before it has cured fully itself. Rushing the schedule to hit a tiling or screed date is the root cause of most early waterproofing failures.

Q: Should site engineers photograph waterproofing before it's covered?

Yes. Dated photographs of completed membrane, upstands, and detailing before cover-up are the single most useful record for resolving any later dispute about whether waterproofing was actually installed to specification.

Q: Who is responsible for waterproofing defects discovered after handover?

This depends on the contract's defects liability period and warranty terms. A workmanship warranty typically covers 3 years, which is why it matters to document installation quality and dates clearly at construction stage.

October 5, 2026

Waterproofing that gets inspected before it's covered is waterproofing that can actually be fixed if something's wrong. Once screed, tiles, or backfill go over a membrane, defects become expensive to trace and repair. This checklist covers what a site engineer should verify and photograph before signing off on cover-up, on any Ghanaian construction site.

Why This Stage Gets Rushed

Waterproofing sits on the critical path between structural work and finishes — screed, tiling, plastering all wait on it. When a construction programme slips, waterproofing is one of the first stages to get compressed: substrate prep gets shortened, cure times get ignored, and the second coat goes on before the first has properly set. None of this shows up as a visible problem on handover day. It shows up eighteen months later as a ceiling stain, and by then the membrane is buried under finishes that have to be removed to fix it.

Pre-Application Checklist

Check	Why It Matters
Substrate is clean, dry, and free of laitance	Membrane won't bond properly to dust, oil, or curing compound residue
Concrete has cured to specification before coating	Coating over green concrete traps moisture and causes early failure
Cracks and joints identified and treated	Untreated cracks telegraph through even a properly applied membrane
Correct fall to drain confirmed	No membrane compensates for standing water caused by poor fall
Primer specified and applied where required	Some substrates need a primer coat for adhesion — skipping it voids performance

During and After Application

Check	Why It Matters
Two coats applied at 90 degrees to each other	A single coat leaves pinholes; the second coat closes them
Upstands taken to correct height at parapets and thresholds	Water tracks up walls in heavy rain; low upstands are a common failure point
Adequate cure time before flood-testing or cover-up	Covering an uncured membrane can damage it before it's ever tested
Flood test carried out and documented (wet areas, roofs)	The only way to confirm a membrane holds water before it's covered
Dated photographs taken before screed, tiling, or backfill	The single most useful record if a dispute arises later

Material Quantities to Verify on Site

Confirm the delivered kilograms of coating match the roof area at roughly 0.4 kg per square metre across two coats — verified against a documented 370 m² project at Kpone Katamanso that used 150 kg (0.41 kg/m²). If the delivered quantity implies a single coat or a thin application, flag it before application begins, not after.

Warranty and Documentation

Fest Ghana Limited's workmanship warranty is 3 years and material warranty is 3 years, separate from the system's 20-year design life. Clear, dated documentation of installation quality at construction stage is what makes any later warranty claim straightforward rather than a dispute over what was actually done.

Related Work

See our engineer's guide to waterproofing detail design and waterproofing construction programme planning for the design and scheduling side of this checklist.

Frequently Asked Questions

When should waterproofing be inspected during construction?

Before it's covered by screed, tiling, or backfill — once covered, defects are expensive to trace.

What is the single most common construction-phase waterproofing mistake in Ghana?

Rushing substrate prep and cure times to hit a screed or tiling date.

Should site engineers photograph waterproofing before it's covered?

Yes — dated photos are the most useful record for resolving later disputes.

Who is responsible for waterproofing defects discovered after handover?

Depends on the contract's defects liability period and warranty terms; a workmanship warranty typically runs 3 years.

Related Resources

Need a waterproofing sign-off on your site? Book an inspection or call 0555 548 001.

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