A hammam in mosaic: wet heat for hotels, gyms, clinics and homes

Wet heat is a different trade from dry heat

A sauna is a timber box at 90 °C and low humidity; a hammam is a stone room at 45 °C with the air saturated. The body feels the second as hotter than the thermometer says, because sweat cannot evaporate, and the room has to be built like a swimming pool rather than a cupboard: every surface waterproof, every joint sealed, the floor falling to a drain. The two rooms want different materials, different ventilation and different cleaning, which is why a hotel that wants both gets two rooms off one corridor, not one room asked to do two jobs.

Why the ceiling slopes, and other things the tiler must know

Steam condenses on the coolest surface, which is the ceiling, and drips. A flat ceiling drips on the people; a ceiling sloped at about ten degrees, or vaulted, carries the drops to the wall and down the wall to the drain. That one line of geometry is the difference between a hammam that is pleasant and one that is not. The rest is wet-room discipline: a tanking membrane behind every tile, a slip-resistant floor laid to fall, a drain with a trap that cannot dry out, a bench built in masonry so there is nothing to rot, and a door that opens outwards and cannot be locked from inside. Mosaic suits the curves; large tiles suit flat walls; natural stone is handsome and wants sealing. We draw the setting-out so the tiler's cuts land where nobody looks.

Generator, water, drain, air: the list for your plant cupboard

Hard water matters more here than anywhere else we build. The generator boils mains water, and in Alicante, Mallorca or Cyprus the limescale left behind shortens its life unless the water is softened or the tank is drained and descaled on a schedule. In Porto or Galway the water is soft and the problem is almost absent. We ask for a water report, or test a sample, before we specify the tank.

In a hotel, gym or clinic

A steam room in a commercial setting is used by strangers in turn and runs for hours, so it is drawn for a rota: a floor that can be hosed, a bench that can be wiped, a door glass that staff can see through, a timer that ends the session and a fan that dries the room overnight. Warm wet rooms are where bacteria grow if cleaning lapses, so ask your health authority what water readings and cleaning records it expects for steam rooms, and whether a legionella assessment applies to the generator and its tank. For a padel club or a boutique gym the hammam is the wet alternative to the sauna, and it pairs with a cold plunge pool exactly as the sauna does: three steps from the door.

At home: where the shower was

A domestic hammam is small, two or three people, and it goes where the plumbing already is: a bathroom being refitted, a basement with a drain, a pool house. The cabin shares the room's drainage and the generator sits in a cupboard. A household uses it in sessions of fifteen or twenty minutes and lets it dry between; the cleaning is a rinse and a wipe. For the house that wants dry heat as well, a made-to-measure sauna and a hammam can face each other across a shower, which is how most spa suites are drawn.

Permits, and what the two coasts change

A hammam inside an existing building is usually an interior refit with new plumbing and electrics, which in Spain and Portugal may still need a works notification to the town hall and will certainly need an electrician's certificate; a new pool house or garden room is a different conversation. Ask the local administration what applies to a wet room with a steam generator, and ask your insurer the same. Climate changes the plant less than it changes a sauna: steam at 45 °C is steam at 45 °C in Dublin and in Limassol. What changes is the water, as above, and the drying: an Atlantic bathroom with no extraction will grow mould in a season, so the fan is not optional.

The ranges for the plunge pool and the sauna a hammam shares a corridor with are in the price list; the hammam's own range is in the table above. Build the cold side in the kit builder and add one line about the steam room.