Pop Up vs Pop Down Basin and Bath Wastes: What’s the Difference

Both a pop up and a pop down waste use the same basic action: push down once to seal the drain, push again to release it, with no separate plug to lose or lift out. The difference is in the profile once the waste is sitting open. A pop up waste, like the range from Phoenix, has a small domed cap that sits slightly proud of the basin or bath surface. A pop down waste, the line ART Australia makes under its Pop Down® name, sits flush with the surface in that same open position, with no raised cap to catch on a foot or a hand in the bath.

• Pop up: push-operated, domed cap, sits slightly raised when open. Widely available across Phoenix, Caroma and Decina ranges for both basins and baths.
• Pop down: push-operated, flush profile, sits level with the surface when open. Mainly the ART Australia Pop Down® line, also available for basins and baths.
• Both types have a quick-release cartridge that pulls out for cleaning, so neither is harder to maintain than the other.

Trade tip: a pop down waste’s flush profile is worth the small extra cost in a bath used by kids, since there’s no domed cap sitting proud on the bath floor to catch a foot or knock a toy against.

A basin waste is typically sized for a 32mm outlet (some are dual-rated for 32mm or 40mm), while a bath waste is sized for a 40mm outlet to handle the larger volume of water a bath drains at once. Beyond size, a bath waste also has to account for the space and access under the bath, which a basin waste never needs to consider.

• Basin wastes suit a 32mm or 32/40mm outlet and sit inside a vanity cabinet with straightforward access from below.
• Bath wastes are sized for a 40mm outlet and often need at least 100mm of clearance underneath the bath for the waste and any flexible connector to sit properly.
• A bath waste sometimes pairs with a separate overflow and waste kit, adding an overflow outlet near the top of the bath connected back to the same waste, which a basin waste doesn’t need in the same way.
• Check whether the specific bath needs a flexible connector (to handle the bath shifting slightly under a full load of hot water) before assuming a straight basin-style waste will fit.

A basin or bath with an overflow, the small drainage slot near the top of the bowl or tub, needs a waste rated for that overflow, while a fixture without one needs the plain no-overflow version. Both pop up and pop down wastes come in overflow and no-overflow variants, and fitting the wrong one either blocks the overflow channel or leaves a poor seal.

• Check the basin or bath itself for an overflow slot before ordering. Its presence, not the tap style or waste type, is what determines overflow vs no-overflow.
• An overflow-rated waste still works fine on a fixture with no overflow, but a no-overflow waste should never be fitted to one that has an overflow channel, since it won’t manage the extra water path correctly.
• If replacing an existing waste, matching the overflow status of the original is the simplest way to get it right without inspecting the fixture from underneath.

Match the waste to the finish already running through the room, chrome, matte black, brushed nickel or brushed gold, since both pop up and pop down ranges are available across the same core finishes. Beyond finish, the brand matters mostly for warranty terms and cartridge replacement, since a pop down waste from ART Australia and a pop up waste from Phoenix or Caroma both use the same quick-release cartridge principle but aren’t interchangeable parts.

• Order the waste finish to match the basin or bath mixer, since the two sit in the same sightline and any mismatch is the most visible thing in the room.
• Stick with the same brand’s waste as the rest of that brand’s tapware where possible, since cartridge replacement parts are brand-specific, not universal.

Measure the basin or bath’s existing outlet before ordering a replacement, since a 32mm basin outlet and a 40mm bath outlet aren’t interchangeable without an adaptor. Where a product is listed as dual-rated for 32mm or 40mm, that flexibility covers most standard basins, but a bath almost always needs the full 40mm size.

• 32mm is the standard basin waste size. Some basin wastes are dual-rated for 32mm or 40mm outlets.
• 40mm is the standard bath waste size, and it’s not a like-for-like swap with a 32mm basin waste even if the cap style looks the same.

Trade tip: if replacing a waste rather than fitting a new basin or bath, take the old part with you or check the model’s spec sheet before ordering, since a mismatched thread size means the new waste won’t seat properly.