Melbourne · Plain English
Bathroom renovation terms, explained
The 20 words that turn up on Melbourne bathroom quotes, in plain English — from AS 3740 and the waterproofing membrane to falls, hobs and puddle flanges. If a quote uses a word you don’t know, it is probably here.
Written by MelReno. Checked October 2026.
AS 3740
The Australian Standard for waterproofing domestic wet areas. It sets which parts of a bathroom, laundry or toilet must be waterproofed and how. Every MelReno bathroom is waterproofed to AS 3740 and you get the certificate at handover.
Wet area
Any room where water is used and splashes: bathrooms, ensuites, laundries and toilets. Wet areas need a waterproofing membrane under the tiles.
Waterproofing membrane
A liquid-applied or sheet layer under the tiles that stops water reaching the frame and floor. Tiles and grout are not waterproof on their own; the membrane is what keeps the water in the room.
Bond breaker
Tape or flexible sealant at the joints between walls and floor, so the membrane can move with the building instead of tearing. A missing or failed bond breaker is a common cause of leaks.
Floor waste
The drain in the bathroom floor. Shower floors and, in many bathrooms, the main floor are sloped towards it.
Puddle flange
The collar fitted around a floor waste that the membrane laps into, so water that gets through the grout still drains into the waste instead of under the floor.
Fall
The slope built into a shower or bathroom floor so water runs to the floor waste instead of pooling. Getting the fall right is part of the waterproofing, not just the tiling.
Screed
A sand-and-cement bed laid on the floor to create the fall before the membrane and tiles go down.
Shower hob
The raised step or kerb around a shower base, standard in older Melbourne bathrooms. Removing it means rebuilding the shower floor with a proper fall and a water stop.
Hobless shower (level entry)
A shower with no step at the entry. It relies on the floor fall and a water stop angle to keep water inside the shower area, and is easier to walk into.
Water stop angle
A metal or PVC angle fixed under the tiles at the edge of a shower or doorway, bonded into the membrane, that stops water tracking across the floor.
Recessed niche
A shelf built into the shower wall for bottles. It is a hole in the wet wall, so it has to be waterproofed as carefully as the floor.
Rough-in
The stage where plumbing pipes and electrical cables are run to where the fixtures will go, before the walls are lined and tiled.
Fit-off
The final stage, when the vanity, toilet, tapware, screen and lights are installed after tiling.
Fibro (asbestos-cement sheet)
A wall and ceiling lining common in Melbourne homes built between the 1950s and late 1980s, often behind old bathroom tiles. Some of it contains asbestos. If we find it, we stop, photograph it and give you a written price for safe removal before work continues.
Large-format tile
Usually 600 x 600 mm and bigger. Fewer grout lines and a cleaner look, but it needs a flatter wall and floor and takes longer to lay.
Tile allowance
The amount per square metre included in a quote for the tiles themselves. MelReno bathroom prices include tiles up to $45 per square metre; choose dearer tiles and you pay the difference, shown before you commit.
Semi-frameless and frameless screen
Two common shower screen styles. Frameless uses thicker glass and minimal hardware; semi-frameless has a slim frame on some edges and usually costs less.
Plumbing compliance certificate
The certificate a licensed plumber issues for the plumbing work on the job. You receive it at handover along with the waterproofing certificate.
Fixtures in existing positions
The shower, toilet and vanity stay where they are now. It is the single biggest thing that keeps a bathroom renovation price down; moving them means new plumbing runs.