Bathroom waterproofing basics: what to ask your trades in Thornbury

Waterproofing is hidden once the tiles go down, but it is the most important part of any bathroom, ensuite or laundry renovation. Many older Thornbury homes have bathrooms built before modern waterproofing practices, and leaks into timber floors and walls are a common reason for renovating. You do not need to be an expert, but knowing what to ask helps you choose the right trades. Our Thornbury page has more on planning a renovation near you.

What waterproofing does

Tiles and grout are not waterproof on their own. Water can pass through grout and cracks into the floor and walls. A waterproofing membrane is applied under the tiles to stop water reaching the structure. It is applied to the shower floor and walls, the bathroom floor and other wet areas, and around penetrations such as the floor waste and tapware.

Questions to ask your trades

1. Who is doing the waterproofing, and are they licensed or qualified for it?
2. Which areas will be waterproofed? Ask for the shower, the floor, wall junctions and any other wet areas to be explained.
3. Which membrane system will you use? A recognised system applied to the manufacturer's instructions matters.
4. How will the floor waste and pipes be sealed? These are common leak points.
5. How long does it need to cure before tiling? Rushing this step causes problems.
6. Will I receive a certificate or written confirmation? Keep it with your home records.

Timing in a renovation

The usual order is strip out, plumbing and electrical rough in, wall sheeting, screed and falls, waterproofing, curing, then tiling. Waterproofing must happen after plumbing positions are final, so choose your shower, wall mixers and floor wastes early. Our renovation planning checklist sets out each step.

Choices that affect waterproofing

• Level entry showers need careful falls and a well detailed drain. See floor wastes and linear drains.
• Recessed niches need waterproofing on every face.
• Timber floors in older homes may need extra preparation before a wet area can be built on them.
• Large tiles need a flat, well prepared substrate.

Warning signs in an existing bathroom

• Drummy or loose tiles.
• Cracked or crumbling grout and silicone.
• Stains or swelling on skirting boards outside the bathroom.
• A musty smell or mould that keeps returning.
• Water marks on the ceiling below an upstairs bathroom.

Any of these can mean water is getting past the tiles, and it is worth having the bathroom inspected.

Waterproofing in laundries and ensuites

Laundries and ensuites are wet areas too. A laundry floor, the wall behind the sink and around the washing machine need attention. An ensuite shower needs the same care as a main bathroom. Read our laundry renovation guide and ensuite renovation guide for planning tips.

Close to Thornbury, Preston and Northcote

Our Reservoir showroom is minutes from the inner north. See our local pages for bathroom tiles and tapware near Thornbury, bathroom renovations near Preston and the tile shop near Northcote, or browse all areas we serve.

If you are buying an older Thornbury home, ask the vendor whether the bathroom has been renovated and whether any waterproofing records exist. A building inspection can also flag signs of past leaks.

Products and installation

We supply tiles, tapware and bathware for Thornbury renovations, with a free measure. Installation by our qualified trades, including tiling and the other trades a bathroom needs, is a paid service quoted for your project. Visit our Reservoir showroom, about 10 to 15 minutes from Thornbury, or our Geelong showroom.

More for Thornbury: tiles for Thornbury homes and renovating a Californian bungalow bathroom.

Common questions

Are tiles waterproof?

Porcelain tiles resist water, but grout and joints let water through. A waterproofing membrane under the tiles protects the structure.

When does waterproofing happen in a renovation?

After plumbing, sheeting and falls are complete, and before tiling. The membrane needs time to cure.

What are signs of a leaking shower?

Drummy tiles, failing grout, swollen skirting boards outside the bathroom and recurring mould can all point to a leak.

Who should do the waterproofing?

A qualified waterproofer using a recognised membrane system. Ask your builder or trades who will do it and how it will be certified.

Can you quote my Thornbury bathroom renovation?

Yes. After a free measure we can quote products and installation by our qualified trades, which is a paid service.

Visit us or shop online

See the range in person at our showrooms: Geelong at 35A Ryrie St, Geelong VIC 3220, phone (03) 5223 2765, and Reservoir at 214 Broadway, Reservoir VIC 3073, phone (03) 9867 5051. Both are open Monday to Friday 9:30am to 5:00pm, Saturday 9:30am to 3:00pm, and Sunday by appointment only.

Planning a renovation? Request a quote and a free measure, and ask us to include installation by our qualified trades if you would like it quoted. Prefer to shop from home? Order online with Australia-wide delivery, or pick up from either showroom, usually ready in 2 to 4 days.