Bunding pipes through tanked wetroom floors

29/10/2025

When it is not possible too directly sleave a protruding pipe or waste because the hot and cold are on flexible connections or the bath waste needs movement for installation of the trap, we need isolated bunding.
Below are photos how we have incorporated bunds around pipes using plastic waste and timber. This is to prevent water migrating to the floor below if it is allowed to get between a tile and the surface tanking.

In these photos bunding has been achieved in a few ways.

Pictures 1.0 to 1.4
We have used 50mm plastic waste solvent welded to a 1.5mm ABS plate with a hole drilled through it then bonded to the ply floor with MitreBond.

Around the bath waste the carpenter has made a timber bund which was tanked around with Seal-Strip then overlade with polyethylene smoothed into a wet cement / flexbinder sealing membrane.

Bunding pipes under a freestanding bath 1.0

Bunding pipes under a freestanding bath 1.1

Bunding pipes under a freestanding bath 1.2

Bunding pipes under a freestanding bath 1.3

Bunding pipes under a freestanding bath 1.4

Pictures 1.5 to 1.9
Position change of vanity hot and cold with flexible connections.

A section of the tanked ply floor was cut out; two holes were cut in a new piece of ply slightly bigger than the 50mm plastic waste pipe.

The ply was screwed down and the waste pipes pushed tight into the aperture, Alfix pipe sleaves are used to provide a seal around the waste pipe and then tanked to overlap the existing tanking.

The hot and cold pipes can now move freely with the aperture without the floor tanking being breached.