Bathroom Waterproofing Before Tiling in Ghana — The Complete Guide (Do This Before You Ever Grout)

The tile is not the waterproof layer. Say it out loud, because 90% of homeowners assume that once tiles are down, the bathroom is waterproof. It is not. Tile is a decorative surface. The grout between tiles is porous. The silicone at internal corners has a 2–5 year service life. Water gets past all of them within months of installation.

The actual waterproof layer must live underneath the tiles. If it isn’t there, every shower for the next 20 years is soaking your concrete slab, corroding the reinforcement steel, and eventually leaking into the ceiling of the room below.

This guide shows you exactly what should happen before your tiler starts — in the correct order, with the right materials.

Why Ghanaian Bathrooms Leak So Often

Four things about Ghanaian bathrooms make them harder to waterproof than the same room in a temperate country:

• High water use — bucket bathing, multiple daily showers per household, and constant humidity keep the slab wet for hours every day
• Concrete slab construction — unlike timber floors that dry out, concrete holds moisture indefinitely once wet
• Cheap tilers who skip the membrane — “the tile is enough,” they tell you, because installing the membrane doubles their labour
• Silicone at every internal corner — cracks and fails within a few years and nobody notices until water is dripping through the ceiling below

The good news: doing it right doesn’t cost much more than doing it wrong. And it saves you the GHS 25,000–80,000 rebuild that comes with a failed bathroom slab.

The Correct Order of Work — What Must Happen Before Tiling

Step 1: Slab is fully cured and level (or falls to drain)

The concrete slab must be cured at least 21 days before waterproofing. The floor must fall gently toward the drain at approximately 1:100 gradient — not flat, not falling away from the drain. If the slab is level or falling wrong, install a screed correction layer first.

Step 2: Clean and prime the surface

All dust, oil, cement laitance, and loose material must be removed. The clean concrete surface is then primed with an acrylic-modified primer designed to bond your waterproof membrane to the slab.

Step 3: Detail the drain, corners, and pipe penetrations

These are the highest-risk zones — water will find them first. Before applying the main membrane:

• Around the shower drain: a preformed drain flange or a strip of butyl rubber tape that seals the drain body to the surrounding slab
• All internal corners (wall-to-floor and wall-to-wall): a strip of butyl tape as a bridging layer, chased into the coating
• Around every pipe penetration: butyl tape wrapped around the pipe and dressed onto the slab

Step 4: Apply the waterproof membrane

Two-coat polyurethane liquid membrane applied by brush or roller. First coat covers the entire floor and walls to at least 300 mm above the highest water contact point (typically 1,800 mm for shower walls, 300 mm for other bathroom walls). Second coat applied perpendicular to the first, encapsulating all the pre-treated details.

Step 5: Curing period before tiling

Wait 48–72 hours for the membrane to fully cure before tiling starts. Do not shortcut this — tiling over a partially cured membrane causes bond failure between the membrane and the substrate.

Step 6: Tiling with the right adhesive

Use a polymer-modified tile adhesive that is compatible with the waterproof membrane. Standard cement mortar is not the right product for this application — it doesn’t bond well to the membrane surface.

Step 7: Grout and silicone at internal corners

Sanded grout in tile joints. Silicone — not grout — at every internal corner (wall-to-floor, wall-to-wall, wall-to-ceiling). Grout at internal corners will crack within a year because the tiles on either side of the corner move relative to each other.

Cost Breakdown for a Standard 6 m² Bathroom

ITEM	TYPICAL COST (GHS)
Surface preparation + primer	400 – 700
Butyl tape at drain, corners, penetrations	350 – 650
2-coat polyurethane membrane, floor + walls to 1.8 m in shower zone	2,400 – 3,600
Labour (2 days on site)	1,800 – 2,800
Total waterproofing (excluding tiles + tiling labour)	GHS 4,950 – 7,750

This is the cost of doing the waterproofing properly on a 6 m² bathroom. Compare to the cost of ripping out tiles, chipping out the failed slab area, replacing corroded reinforcement, re-pouring concrete, and re-tiling in 5 years: GHS 30,000–65,000.

Where Most Tilers Get It Wrong

• Skipping the membrane entirely. “The cement is thick enough.” It isn’t.
• One coat instead of two. Halves the dry film thickness and the design life.
• Only membrane on the floor, not up the walls. Water splashes past the tile grout up to 1,800 mm on shower walls. That whole zone needs the membrane.
• No pre-treatment at the drain. The number-one leak point on every tiled bathroom floor.
• Grout at internal corners instead of silicone. Guaranteed to crack.
• Not waiting for cure. Tiling over uncured membrane causes bond failure between membrane and slab — the membrane lifts, the tiles crack.

How to Vet Your Tiler

Ask your tiler these five questions before you sign anything. Their answers tell you whether they know what they’re doing.

1. Are you installing a waterproof membrane under the tiles?
2. Which brand and how many coats?
3. Do you pre-treat the drain and corners with butyl tape or preformed accessories?
4. How high up the shower wall does the membrane go?
5. What warranty do you give on the waterproofing?

If any answer is vague, dismissive, or shifts to “you don’t need that,” find another tiler. Or hire us to install the waterproofing before your tiler does the tiling — we work with tilers all across Accra and there’s no conflict.

Book a Bathroom Waterproofing Service

We do bathroom waterproofing as a specialist service — we prep and waterproof the slab, then hand off to your tiler for the finish. Or we can do the whole job end-to-end.

• Phone: 0555 548 001 or 0241 737 026
• WhatsApp: Send us your bathroom dimensions and layout
• Book online: Book a bathroom waterproofing service
• Shop products: 10kg PU coating · Butyl waterproof tape

Festghana Waterproofing Solution Company Limited (trading as Fest Ghana Limited) provides bathroom, wet-room, and shower waterproofing services across Ghana. Workmanship warranty on every job.