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How to Professionally Waterproof a Wetroom
British Standard BS 5385‑1 mandates tanking substrates in wet areas before tiling.
Tanking is extremely important, no matter how good the tiling and grouting is, factors including movement and thermal expansion can cause the finest of cracks that can let water track through, a tanking membrane protects your home from damp, mould, and structural damage.
No matter which of our tanking systems you decide to install the aim is the same, to create one continuous tanking sheet membrane over the entire wet area. Minimum coverage is at least 1000mm up the walls and 1000mm onto the floor from the wet trays edge.
It is preferable to tank beyond this, or even tank the entire room, depending on water flow or the potential splashing of water beyond the determined wet area.
These guides assume that all previous works have been carried out appropriately, the substrate has been prepared correctly, the tray is laid flat, is level with the rest of the floor and has no movement.
Option A - Innovations Paint-On Tanking Wetroom System
Easy to use paint on tanking compound that once applied will dry into a flexible rubber sheet membrane.
Ensure the substrate is sound, free of any contaminants and remove any loose material.
Check there are no significant irregularities, any gaps should be filled using a cement based tile adhesive.
Please note - When applying the tanking compound, thicker is not better!
All that is needed is a nice even coat, applying the compound too thick will only impede drying times and does not offer increased performance.
Prime the entire wet area and let dry.
Apply the first coat in one direction; embed corners, tapes & pipe collars during application.
Allow to dry overnight or may be brushed over after 3 hours.
Apply a second coat perpendicular to the first.
Allow to dry for 24 hours before tiling.
Option B - Hydromat Sheet Membrane Wetroom System
Butyl self adhesive sheet membrane that may be tiled over straight away
Please note - The Hydromat system components are extremely high tack, care should be taken when handling to ensure no contact is made between them prior to being laid in the correct position.
The Hydromat sheet membrane once laid must be rolled over to ensure adhesion.
Ensure the substrate is sound, free of any contaminants and remove any loose material.
Check there are no significant irregularities, any gaps should be filled using a cement based tile adhesive.
Prime the entire wet area and let dry.
Apply the internal/external corners.
Apply joint tape into the corner wall/wall join, overlap the tape onto the internal corner by at least 50mm.
Apply joint tape into the corner floor/wall join, overlap onto the internal corner by at least 50mm, but do not overlap onto the vertical tape.
Starting on the wall first, from the corner, apply joint tape at 1000mm centres, overlap the wall tape onto the floor tape, down to the floor.
Starting in the corner apply the membrane onto the wall, where the membrane butt joints, ensure to overlap it onto the tape by at least 70mm, avoiding gaps greater than 5mm between the sheet membranes.
Now on the floor, apply joint tape at 1000mm centres, overlap it onto the floor/wall tape up to the wall.
Before the the membrane can be laid, the interface between the membrane and the floor drain must be considered.
Please read the "Common drain & membrane interfaces" section now and apply it during the next part of the installation.
Starting in the corner apply the membrane onto the floor, where the membrane butt joints overlap onto the tape by at least 70mm, avoiding gaps greater than 5mm between the sheet membranes.
Apply Butyl Sealant to all gaps/joints. This sealant does not cure solid, it will remain permanently plastic.
Tile directly over once it's laid correctly.
Common Drain & Membrane Interfaces
The Purus Minimax 2-part drain drain features a clamping ring, remove the clamping ring, mark the centre of the drain when laying the membrane and cut a 107mm diameter hole in it.
Press the membrane into the drain then install the clamping ring to secure it.
For other drains with clamping mechanisms please refer to your drain instructions.
For drains that have upstands, cut the membrane to fit it around the upstand, ensure to leave a gap no greater than 5mm and apply Butyl Sealant.
Drains without an upstand may also be used by taking the membrane at least 30mm onto the body of the drain and applying butyl sealant to the edge of the membrane.
Common Drains & Membranes Interfaces
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