Wetroom Installation

1. Initial Planning / Suitability of your Floor

Both timber and concrete are suitable substrates for wetrooms.

A wetroom does not need to cover the entire bathroom or bedroom area. It can be restricted to a corner of a bathroom or indeed a corner of a bedroom for an en-suite. A key benefit of our system is the need to waterproof only the "wet" area reducing costs to a third of normal levels.

Whilst a concrete floor needs only sharp projections removing, timber requires floorboards or chipboard lifting and discarding around the wet area. Lay a perimeter strip of plywood around the underlay (as shown in the drawing), all screwed at 230mm (9") centres or reinforce the floor by overlaying with 18mm plywood screwed as before.

Thinking of wall tiling? Stick a length of carpet tape on the wall and strip it off. If there is paint or plaster stuck to it the tiling will not be safe or secure so apply tile backer board.

Cut-away Floor Section of Wet Area

2. How to Form the Waterproof Membrane

On Tile Backer Board (tbb)
Simply use Flex Tape and Flex corners on all joints and wall/floor joints

On Plywood
Use Granfix tanking liquid or BSA or WOP membrane (see membranes)

It is optional to waterproof the whole floor and walls. It is essential to do the "wet" area (marked by X-X-X-X in wetroom plan view above) and 500-950mm up the walls.

3. What Sized Area Should be Tanked / Waterproofed?

To create the "wet" area simply double the underlay area plus a bit. If the underlay is 1 sq mtr then waterproof just 2-2.3 sq mtrs thus keeping costs down.
A small step will be formed at the edge of the membrane as follows:

• Granfix - 1mm thickness
• BSA - 2mm thickness
• WOP membrane - 0.15mm thickness
• Marmox Board (tbb) - 4-50mm thickness

For tiling, a 4mm step is easily made up by the tiling adhesive. For vinyl it has to be smooth and level so membrane the whole floor to achieve this. Overlaying the concrete or timber with Marmox tile backer board (tbb) 6, 10 or 20mm thick will form a membrane with joists and edges taoped with Flex Tape.

4. Installation