How to Waterproof a Kitchen

A kitchen uses large amounts of water every day, so waterproofing performance matters and must be handled during renovation. How is kitchen waterproofing done? CHINENG walks through the process below.

How to waterproof a kitchen

1. Clean the substrate: remove dust and debris before waterproofing. Pre-wet the surface with water if needed, but leave no standing water.

2. Floor slurry coating: detail floor drains, pipe penetrations, and wall corners first. Then brush the first coat in one direction with film thickness under 1 mm so it dries evenly without blistering or cracking. After drying, apply a second coat at right angles to avoid misses, then run a water-ponding test the next day.

3. Wall slurry coating: waterproof walls to about 180 cm to protect against splash from taps. The method matches the floor, but use a wall-grade coating.

4. Floor fall: design a slope so water drains to the floor drain; keep the waterproof coating intact and clean the floor regularly.

Waterproofing precautions

1. Re-waterproof when retileing

After removing old tiles, level with cement mortar before waterproofing so coating thickness stays even. Clean thoroughly, then brush polyurethane waterproofing two to three times.

2. Do not damage the existing membrane

A broken membrane causes later leakage. Protect it during renovation and repair immediately if damaged; rebuild it if it is already compromised.

3. Waterproof pipe chases in walls

Where pipes and drains pass through slabs, detail the membrane carefully. Chase walls larger than the pipe, plaster the chase smooth, then coat with polyurethane. Slope the floor toward the drain. Avoid relocating drains and soil stacks during fit-out, which can cut the membrane and cause leaks.

That is CHINENG’s guide to kitchen waterproofing. If kitchen renovation is a concern, contact CHINENG for engineering support.