Steam rooms tanked before they are tiled

The tank

Liquid membrane over the slab and up the walls past the ceiling junction, taped at every corner and change of plane, screed falling at least 1:50 to the drain, then tile or stone. The ceiling pitched 3 to 5 degrees so condensate runs to the walls.

The membrane needs a full day between coats and a day before tiling. Any programme that does not allow for that is a programme that will leak.

Kenyan water

Water hardness varies enormously across the country, and many properties are on borehole supply with chemistry quite unlike the mains. We test at the property before specifying the generator, because the descaling interval depends on it and getting it wrong costs a generator.

Boreholes in parts of the Rift Valley also carry high fluoride and dissolved solids, which is a different problem again and one worth knowing about before you commission a steam room on one.

Coast versus highlands

On the coast the room will not dry itself — humidistat extract, continuous vapour barrier, sealed penetrations. In Nairobi a run-on timer is usually sufficient because the air is drier and the nights are cool.

That difference is worth real money and it is one of the few places where building in the highlands is simply cheaper.

In short

• Membrane over slab, walls and ceiling junction, taped at every corner
• Water tested at the property, including borehole supplies
• Humidistat extract on the coast, run-on timer inland
• Full cure time respected — a fortnight programme is a programme that leaks