Finlandia JM-30, JM-17 manual Insulation and Wall Materials of the Sauna Room, Sauna Room Floor

2. THE SAUNA ROOM

2.1.Insulation and Wall Materials of the Sauna Room

In an electrically heated sauna, all the massive wall surfaces which store plenty of heat (such as bricks, glass blocks, plaster etc.), must be sufficiently insulated in order to keep the heater output at a reasonably low level.

A wall and ceiling construction can be considered to have efficient thermal insulation if:

• the thickness of carefully fitted insulating wool inside the house is 4" (100 mm) minimum 2" (50 mm).

• the moisture protection consists of e.g. aluminium paper with tightly taped edges. The paper must be fitted so that the glossy side is towards the inside of the sauna.

• there is a 3/8" (10 mm) vent gap between the moisture protection and panel boards (recommendation).

• the inside is covered by 1/2" – 5/8" (12–16 mm) thick panelling.

• there is a vent gap of a few millimetres at the top of the wall covering at the edge of the ceiling panelling.

When aiming at a reasonable heater output, it may be advisable to lower the ceiling of the sauna (normally 6'–10 11/16" (2100 mm), minimum height 59 1/16" (1500 mm). As a result, the volume of the sauna is decreased, and a smaller heater output may be sufficient. The ceiling can be lowered so that the ceiling joists are fixed at a suitable height. The spaces between the joists are insulated (minimum insulation 4" (100 mm) and surfaced as described above.

Because heat goes upwards, a maximum distance of 38" (970 mm) is recommended between the bench and ceiling.

NOTE! Consult fire-extinguishing authorities to find out which part of the fireproof wall may be insulated.

NOTE! The protection of the walls or ceiling with heat protection, such as mineral board fitted directly on the wall or ceiling, may cause the temperature of the wall and ceiling materials to rise dangerously high.

2.1.1. Room construction – general information

FRAMING	2" x 4" Dry Douglas Fir, 16" o.c.
CEILING HEIGHT	No higher than 7' 0".
INSULATION	R11 Fiberglas with foil back in
	walls and ceiling, foil facing
	into room.
DRYWALL	See local codes. Is not
	required in most residences.
	See local codes for
	commercial. If drywall is used,
	apply 1" x 2" nailers so that
	wall and ceiling boards can be
	attached to solid wood.
PANELING	Use kiln-dried, clear, T & G
	softwood such as California
	Redwood, Western Red Cedar,
	Alaska yellow Cedar, with
	moisture content not exceeding
	11%.

Figure 4. Sauna room
BENCHES	Use matching wood of vertical
	grain with 2"x 2" tops – 1/2"
	spacing - and 2"x 4" facing,
	fastening from bottom to prevent
HEATER	burning of bathers.
GUARDRAIL	Use matching softwood
	of 1" x 2" or 2" x 2".
DOOR	Must open out and should not
	have a lock. Size – 2' 0"x 6'8" with
	fir rails and double sealed,
	tempered glass.
ROOM LIGHT	Should be a vapor proof, wall-
	mounted type, with rough-in box
	mounted flush with inside paneling.
	It should mount 6" (150 mm) from
	ceiling, not directly over the Sauna
	heater, and not over upper
	benches; light bulb should not
	exceed 75 watts.

Note! Receptacles OR PLUGS are not allowed in a Sauna room. If a speaker is installed in a Sauna room, it should not be installed higher than 3' from floor, away from the Sauna heater (consult manufacturer for ratings).

2.2. Sauna Room Floor

Due to a large variation in temperature, the sauna rocks disintegrate in use.

Small pieces of rock are washed down on the sauna room floor along with the water thrown on the rocks. Hot pieces of rock may damage plastic floor coverings installed underneath and near the heater.

A light-cocoured joint grout, used for a tiled floor, may absorb impurities from the rocks and water (e.g iron content).

To prevent aesthetic damage (due to the reasons presented above) only dark joint grouts and floor coverings made of rock materials should be used underneat and near the heater.

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