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Bathroom Renovation Guide

Bathroom Glossary


Get to know these trade lingo favourites with thanks to smarterBATHROOMS+



S-trap refers to a 100mm waste that exits a toilet suite through the floor from beneath the toilet suite.


P-trap refers to a 100mm waste that exits a toilet suite through the wall behind the toilet suite.

Bottle traps

Bottle traps are exposed wastes that sit underneath basins.

Rough in

Rough in refers to the process whereby plumbing waste and water pipes are concealed in the walls and floor of a bathroom.


A screed is used to level an uneven floor in preparation for tiling. Not only are floors not level in many homes, but walk-in showers are also now the design norm, and a screed is used to both level the floor and ensure that water flows in the right direction. Screeds are usually 40-80mm thick and consist of a sand and cement mixture often with a layer of re-enforcement built in.

Rimless toilet

A rimless toilet suite is a (new) optimally hygienic toilet design that circulates water from a single flushing point with a precise and splash-free flow, avoiding grime and bacteria build up with less holes, angles and edges on the pan’s surface.

Above counter basin

Above counter basins sit on top of vanity or floating bench tops and are often beautiful feature basins.

Grey water

Grey water is water from a basin, shower, bath or washing machine – this is deemed fit for disposal (or use) in a garden after it has gone through some filters.


To ‘retrofit’ means finding another product to replace existing product without having to dramatically modify the existing layout.

Black water

Black water is dirty water from a toilet and requires purification.

Back to wall

A back to wall toilet suite sits flush against a tiled or plaster wall, with no exposed pipes. 

Hidden / Inwall cistern

A hidden cistern refers to a toilet suite where the cistern (or tank) is concealed within a wall. This type of toilet requires access for servicing via an access panel.


A trap is used to prevent nasty smells entering the bathroom from the sewer. A trap works by creating a water block in an “s” bend, preventing gases from passing.

Set out

A set out is done before the rough in works are done. The plumber allows for the thickness of plaster and tiles to make sure all the fittings are in the correct position. This is a critical step and should be double and triple checked.


A diverter is used to switch the water supply between two different outlets such as a shower and bath or two different shower heads within one shower.

Tile lip

A tile lip is a small raised tile edge usually raised to prevent water leakage (for instance on entry to a shower).

At smarterBATHROOMS+ we remove tile lips to create more modern, ergonomic flat surfaces.


Semi-recessed basins sit half on and half off the front of vanities or floating bench tops. They are generally used in narrow bathrooms where space is a consideration.

Lock up

The stage of a build where all the windows and doors are secured, and you can ‘lock up’ the house.

Fit off

Fit off refers to the installation of various fixtures e.g. Shower heads, basins, toilets, to the in wall plumbing system.