Caroma Wastes & Traps

It depends on the specific basin. Caroma basins are made with either a 32mm or 40mm waste outlet depending on the model, so the correct waste size is determined by the basin the waste is being matched to, not a single standard across the whole brand. Always check the outlet diameter listed on the basin's own specification sheet before ordering a replacement or upgrade waste, fitting the wrong size won't seal properly against the outlet.

The waste sits in the drain hole at the base of the basin, sealed with a washer or plumber's putty, and connects underneath to the trap and waste pipe. While the waste itself is a relatively simple fitting, this is still plumbing work covered by Australian regulations, and a licensed plumber should carry out the installation and connection to make sure the seal is watertight and the trap is correctly fitted. This also matters for warranty, a basin or waste fitted outside code requirements can affect what's covered if a fault develops later.

Pop up wastes (operated by pressing down on the waste itself to open and close the drain) are the more common choice in current Australian bathrooms because there's no separate plug to misplace and the mechanism sits flush with the basin for a cleaner look. The alternative is a pop down waste, used on ART Australia-style designs, which drains via a flush-profile cap rather than the domed cap typical of a pop up. Both are reliable when properly installed, the choice mostly comes down to the look you want and what the basin's outlet is designed to take.

Measure the internal diameter of the basin's drain hole where the waste will sit, this will almost always come out to 32mm or 40mm on a standard Australian basin. It's worth double checking against the basin manufacturer's listed specification rather than measuring alone, since a slightly worn or non-standard hole can be misleading with a tape measure. The thread size on the underside (commonly 1¼" or 1½") also needs to match the trap you're connecting to.

A Caroma basin doesn't strictly require a Caroma-branded waste, a correctly sized 32mm or 40mm waste from another quality brand will generally fit and function. That said, buying the matching Caroma waste removes any guesswork on outlet fit and finish matching, and is the safer choice if you're not confident measuring the outlet yourself. If you're also replacing the trap, check caroma-basins for the basin range this waste is designed to pair with.

The waste is the fitting at the bottom of the basin bowl that plugs and drains the water, while the trap is the separate pipe fitting underneath that holds a small amount of water to stop sewer gases coming back up through the drain. Both are needed for a working, code-compliant basin installation, and on Caroma basins the two need to be checked together, since trap thread size has to match the waste's outlet connection, not just the basin's drain hole.