Linear drain waterproofing. Where the membrane goes.

Linear drains are popular because the floor falls one way and the tiles stay whole. They also move the most important join in the bathroom to a long, narrow slot where it is hard to see.

Two kinds of channel

Channel with a flange or upstand of 50 mm

The membrane bonds onto the flange and runs into the outlet

Channel with none

The membrane runs under the channel to a recessed flange at the pipe

The second kind is common. The channel is then a tray sitting on top of the waterproofing, not part of it. Water that gets past the channel has to find the flange below.

Against a wall

A channel with no flange set against a wall has to meet the same membrane heights up the wall as any other shower junction.

Before the channel goes in

1. Ask which kind of channel it is, and get the installation sheet.
2. Set and check the recessed flange at the pipe, as for any floor waste.
3. Take the membrane into the outlet, then fit the channel.
4. Flood test with the pipe plugged below the flange.

The flange rules are in puddle flanges: what AS 3740 requires, and the test method is in flood testing a membrane.