Why it matters more here
Waterproofing is the stage of a bathroom renovation that nobody sees after the tiles go on. Everywhere, it decides whether the room lasts. In the Highlands, two things raise the stakes.
Timber floors. Many older Bowral, Burradoo and Moss Vale houses sit on suspended timber subfloors. On a concrete slab, a slow leak mostly damages the finishes. On a timber floor it soaks the joists and bearers below — and because it happens out of sight, it can go on for years.
Cold and damp. A Highlands bathroom sees heavy condensation through winter. Moisture that gets behind tiles dries slowly in a cold house. The combination is exactly what timber rot needs.
What was there before
Most older Highlands bathrooms were built before modern wet-area membranes were standard practice. Many were tiled over fibre cement or render with nothing more than the tile and grout keeping water out. Later renovations in the 1970s and 1980s often used early membranes that were applied thinly, not turned up the walls far enough, or not dressed properly into the waste.
So when a thirty- or forty-year-old Highlands bathroom is opened, finding no functional waterproofing is not unusual. Finding water damage in the frame or subfloor is not unusual either.
Signs your shower is leaking
- Swollen, stained or soft skirting boards outside the shower wall.
- Flaking paint or bubbling plaster in the hallway or bedroom next door.
- Tiles on the bathroom floor that sound hollow or have lifted.
- Grout that cracks repeatedly in the same line.
- A musty smell that does not clear with ventilation.
- Damp, darkened or soft timber in the subfloor below the bathroom.
That last one is worth checking yourself if you have access. Take a torch and look under the bathroom. It tells you a great deal.
What the process involves
Preparation. The substrate must be sound, clean and dry. On a timber floor that means compressed fibre cement sheet or an equivalent wet-area substrate properly fixed to sound joists — not over timber that is already soft.
Falls. The shower floor is screeded so water runs to the waste. A level-entry shower needs this set out carefully, often with a recessed floor or a linear drain.
Bond breakers and junctions. The internal corners and floor-to-wall junctions move. Bond breakers or flexible sealant go in so the membrane can accommodate that movement rather than tear.
Membrane. Applied in the specified number of coats to the specified thickness, turned up the walls to the required heights, and dressed into the waste flange and around every penetration.
Cure. Each coat must cure before the next, and the whole membrane before tiling. In a Highlands winter this takes longer than the product's warm-weather figure. We allow for it.
Flood test where appropriate. The shower recess is filled and checked before any tile is laid.
Certificate. A compliance certificate from the licensed applicator.
Why rushing it is the most expensive mistake
Every day of cure time feels like a day lost. It is not. A membrane tiled over before it has cured can fail inside the wall, and nobody finds out until the skirting outside the room starts to swell — by which time, on a timber floor, the joists underneath may be damaged too.
Fixing that means taking out a finished bathroom. Allowing an extra day or two in the program costs nothing by comparison.
Laundries count too
A laundry is a wet area under the Building Code. On a timber floor, a burst washing-machine hose empties straight into the subfloor. The laundry floor gets a membrane on our jobs for the same reason the bathroom does.
Where it fits in the program
Waterproofing follows strip-out, frame and floor repairs and rough-in, and comes before tiling. The process page shows where it sits in a typical four-to-five-week Highlands job.
Call 02 4210 5289 or send the room details through.