Basin Wastes with Overflow

Basin wastes with overflow guide

A basin waste with overflow is a plug and waste made to work with the small overflow hole near the rim of a basin. When the basin fills past a safe level, water runs through that hole and down to the drain instead of over the edge. This collection holds the wastes that suit basins with an overflow: universal wastes that fit basins with or without one, convertible wastes with an adjustable overflow, wastes sold with the overflow included, and a few made for particular basin ranges. The questions that matter are the same for every waste: does the basin have an overflow, is the outlet 32mm or 40mm, and does the waste suit that arrangement. The sections below cover what to check before you order. For every type of basin waste, start at basin wastes.

What a basin overflow is

An overflow is a small hole near the rim of the basin. It is the outlet that drains excess water if the tap is left running, and not every basin has one. Bathroom basins often do, while kitchen sinks and other basins usually do not. Basins with an overflow are common in apartments and family bathrooms, although basins without one are the more common arrangement.

To check your own basin, look inside the bowl just below the rim. A slot or hole there is the overflow. If the rim is smooth and the bowl is unbroken, the basin has no overflow. Then confirm that the waste you choose is made for overflow basins.

Slotted and unslotted wastes

The words slotted and unslotted decide which waste fits. A slotted waste has openings in its body, so overflow water can pass into the drain whether the waste is open or closed. An unslotted waste is watertight when closed. It suits a basin with no overflow, and a basin with an overflow needs the slotted kind.

One case is worth knowing. If the basin has an overflow hole that needs a separate connection to work, choose an unslotted waste. Many wastes in this collection sidestep much of the question, because they are universal and suit basins with or without an overflow. The overflow wording on the product is the thing to check.

Do you need an overflow in a bathroom sink

That depends on the basin, since the overflow is part of the basin and not an option on the waste. A basin with an overflow hole needs a waste that handles it. A basin without one does not. This page states no Australian rule on whether a basin must have an overflow, so ask your plumber or the basin's maker if the question matters for your job.

The choice you do control is the waste. A universal waste, suiting basins with or without an overflow, is the lower-risk pick when you are not sure, and many wastes in this collection are exactly that. A waste made only for a basin with no overflow will not suit an overflow basin.

Universal wastes

The word universal means different things on different products, and each defines it for itself. The Nero universal pop up waste suits basins with or without an overflow, with a standard 40mm bottle trap connection, and it fits basin waste holes from 42mm to 58mm. The ADP universal mushroom waste suits 32mm and 40mm overflow and non-overflow wastes, with a 40mm connection and a removable plug, for baths or basins. The Turner Hastings waste is a universal 4-in-1 that suits basins with a 40mm or 32mm outlet, with or without an overflow, with a solid brass body and spring construction.

Convertible wastes

Some wastes change to suit the basin. The Fienza dome pull-out wastes in this collection are convertible for use with or without an overflow, with the overflow adjusted by a centre screw. They suit a 32mm or 40mm outlet, and the 40mm size uses an adaptor that comes with the waste. The entire top section pulls out for easy cleaning and draining.

Wastes sold with the overflow included

The Meir universal all-in-one waste suits both basins and baths, with the overflow included. It is made of brass, has a removable grate, and is WaterMark approved to AS/NZS 3718:2005. For a basin that has an overflow hole, a waste sold with the overflow included answers the question in the product itself.

The ART Australia wastes in the collection suit basins with a 32mm or 40mm outlet, with or without an overflow, and have a quick-remove cartridge. They are made of brass and were previously known as Bounty Brassware.

Wastes made for particular basins

Two sets of wastes are narrower. The Clark 40mm pop up waste is for wall hung, under counter, semi-recessed and semi-inset basins only, and it can be used on basins with or without an overflow. Some Caroma wastes are designed to fit the Liano II, Urbane II or Contura II basins, and the Caroma waste suits basins with or without an overflow.

When a waste names a basin range or a basin type, treat it as a requirement and not a suggestion. A waste for a semi-inset basin may not suit a vessel basin, and a waste made for one range may not seat properly on another.

Sizes: 32mm or 40mm

Two sizes dominate. The size 32mm is the most common basin outlet size, and a qualified plumber should confirm it. Basins are usually 32mm and baths 40mm, which is why universal wastes are sold for both. Most Australian basins use a 32mm or 40mm waste, measured at the part inside the basin, and a 32mm waste can connect to 40mm pipework with an adaptor.

The same pattern holds across the range. Phoenix wastes in this collection suit standard and overflow basins and baths specifying a 32mm waste, and they connect to 40mm pipework. The Fienza 40mm size needs the included adaptor. For the sizes in detail, see 32mm outlet basin wastes and 40mm outlet basin wastes.

Are overflow holes a standard size

There is no standard size for the overflow hole. The size that is standard is the waste outlet, 32mm or 40mm, not the overflow slot. Treat the overflow as part of the basin's own design. If you are matching a waste to a basin with an unusual overflow, check the basin's specification or ask a plumber before you buy.

Pop up and pop down wastes

Pop up and pop down describe the plug action. At The Blue Space, a pop up waste has a domed cap that sits proud of the basin floor when open, and a pop down waste sits flush when open. The two styles are in pop up basin wastes and pop down basin wastes.

The ART Australia pop down waste sits flush in the open position and has a quick-remove cartridge. The Phoenix wastes work by pushing the waste to pop it up and down. Either action can come with or without an overflow, so the plug style does not decide the overflow question.

Finishes and how they are made

Finishes include chrome and gloss white, matte black, the brushed finishes in nickel, gold, brass and copper, gun metal and urban brass. Some are PVD and others are electroplated. The Phoenix finishes are electroplated to ensure the colour lasts, while the Caroma brushed nickel and brushed brass are PVD, as are the gunmetal and brushed bronze.

Fitting a waste to an overflow basin

Fitting follows the basin. Measure the outlet at the part inside the basin, then match it to a 32mm or 40mm waste. Check where the overflow runs and whether the waste you chose is slotted or universal. Follow the instructions supplied with the waste, then test it by filling the basin to the overflow level and watching the connection below for drips.

WaterMark applies where required, and licensed work is required in WA. The Meir waste is WaterMark approved to AS/NZS 3718:2005. Ask a licensed plumber if you are unsure what your job requires.

Thick vanity tops

Basins set into a thick stone or timber top can leave a standard waste short. Extended wastes exist for thick vanity tops. If your basin or benchtop is thick, look for a stated thickness range or an extended thread before you order, and measure the depth from the top of the basin hole to the underside of the bench.

Matching a waste to the brand

If you are buying tapware from one maker, a matching waste keeps the finish consistent. These makers have their own pages: Phoenix wastes and traps, Meir wastes and traps, ADP wastes and traps, Caroma wastes and traps, Clark wastes and traps, Nero wastes and traps and Turner Hastings wastes and traps.

Cleaning and care

A waste with a pull-out top is the easiest to keep clear. The Fienza wastes have an entire top section that pulls out for cleaning and draining, so debris is easy to reach. Wipe the waste dry, use a mild or citrus cleaner, and avoid abrasives. Hard water scale can stop a seal working, so rinse and dry after cleaning.

If the basin overflows slowly or smells after a long fill, the overflow channel behind the rim may hold soap and scale. Run warm water through it with a soft bottle brush and a mild cleaner, and keep abrasive powders away from the glaze. The same habit keeps a rarely used guest basin working, because an overflow that has never carried water is the one that surprises you the day a tap is left running.

How to choose

Start with the basin. Look for the overflow hole and note whether the basin has one. Then measure the outlet and decide between 32mm and 40mm, remembering that the pipework is usually 40mm. Next look for the words with or without overflow, or for a universal or convertible waste. If a waste names a basin range or a basin type, check yours matches.

After that the choice is about finish and plug action: pop up or pop down, and the colour that suits your tapware. If you are comparing across the whole range, return to the basin wastes range and filter by what you need.