Allproof

A puddle flange, also called a leak control flange, is the fitting that joins the waterproof membrane to the floor waste outlet. Without it there is no continuous seal between the membrane and the drain, so any water that gets through the tiles and grout has a path straight past the waterproofing and into the substrate. It is a small part that carries a lot of the risk in a bathroom, laundry or balcony.

Australian wet area practice, covered by standards such as AS 3740 for internal wet areas and AS 4654 for external above ground work, requires the membrane to be terminated and sealed at the floor waste rather than simply finishing near it. A leak control flange is the accepted way of achieving that connection, which is why they turn up on almost every compliant bathroom. Requirements and inspection expectations vary between states and between certifiers, so confirm what your job is being signed off against with your plumber or building surveyor.

A clamp down flange, such as the Allproof TILERITE, mechanically holds the membrane between the flange body and a clamping ring, giving a positive mechanical seal at the outlet. A standard leak control flange relies on the membrane being bonded and dressed over the flange collar around the pipe. Both terminate the membrane at the drain, and the choice usually comes down to the waste and grate you are running, the substrate, and the installer's preference.

The flange is normally set by the plumber when the floor waste and pipework go in, because it has to be fixed to the outlet at the correct height and sit flush with the finished floor level. The waterproofer then dresses the membrane into the flange as part of the wet area system. Agree between the trades who is supplying it before the screed goes down, because retrofitting a flange after the floor is set is expensive, messy work.

Fix the flange to the outlet first and make sure it finishes level with the surrounding floor so the membrane is not bridging a step or a void. Prime and prepare the substrate, then bring the membrane over the flange collar and dress it in with reinforcing fabric or bond breaker wherever the membrane manufacturer calls for it, keeping the fall running toward the waste. Do not leave an unsupported gap between the flange and the substrate, as that is a common point of failure.

PVC leak control flanges are used under both liquid applied and sheet membranes right across the Australian trade, but adhesion depends on the membrane system and how the flange surface is prepared. Some membranes want the flange lightly abraded or primed before the membrane is dressed over it, while sheet systems are detailed differently again. Check the technical data sheet for the membrane you are applying and follow its penetration and flange detailing before you start.

You can order the Allproof range directly from this page. It is focused on leak control and puddle flanges for floor wastes, including the PVC leak control flange and the TILERITE clamp down flange, so it suits waterproofers and plumbers rather than being a general drainage catalogue. Single flanges suit a one off bathroom, while the boxed PVC flanges are there for builders and waterproofers running multiple wet areas or a full project. Call the team if you are unsure which flange matches the outlet on your job.