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FAQs about Saunas

Sauna planning questions

Don't be intimidated by the thought of building your own sauna - it's not "rocket science" and can be undertaken by anyone with only elementary construction experience. 

If you don't have any building experience you would be advised to ask a neighbour or friend to help you that has some building knowledge. By watching how walls are framed, etc., you will quickly understand the fundamentals of frame building. 

If you use the "step-by-step" procedures on these pages, you should have no difficulty designing your sauna room, and choosing your sauna heater and control. 


Q. "How easy is it to build my own sauna if I have little or no carpentry experience?"
A. "It is not hard to learn the basic carpentry skills needed to build a sauna, or other projects for that matter. Good instruction is available all over the internet. Click here for a complete glossary of terms used in the framing industry. If you want step-by-step framing instructions, click here.

Q. "What is the optimum height for my sauna?"
A. "A ceiling height of 6-1/2 to 7ft is allowed in a sauna. If your ceiling is higher than 7 feet, you should lower it to ensure proper sauna heater operation."

Q. "What length should my studs be to get a 7ft ceiling height?"
A.  "See the chart below, showing each wall component from the floor up to the ceiling. Using this procedure you can determine the stud length for any finished sauna height. (NOTE: the measurements below assume a cedar thickness of 1/2")

Wall Component Height Cumulative Total
2x4 bottom plate 1.5" 1.5"
2x4 stud 80" 81.5"
first 2x4 top plate 1.5" 83"
second 2x4 cap plate 1.5" 84.5"

If you want your ceiling to be only 6-1/2 ft from the floor, simply cut the 2x4" stud to 74" instead of 80". Your ceiling can be built on the floor and then lifted into position on top of the walls and nailed into place there.

With the cedar applied to the underside of the ceiling, this will drop your finished height to 7 ft if you use the measurements in the chart above."

Q. "What size should my sauna be?"
A. "The important thing is bench length because you will want to lay down, so plan on one wall being at least 6 ft long. The other wall can be anywhere from 4 feet (on the small side) to a more comfortable width of 6 or 7 feet."

Q. "What should I know about the door in a sauna?"
A. "Codes state sauna doors MUST open outwards from the sauna and cannot be equipped with any latching mechanism requiring lifting or turning to exit the sauna. Sauna doors are usually equipped with a brass-plated roller latch that allows the sauna door to open merely by pushing or leaning against it. Insulated sauna doors are usually supplied with 1x6" frame, hinges, handles, and door stop molding with all routering done for you. The required rough frame opening for regular sauna doors is 26" X 78"."

Q."Can I purchase a light fixture from my local hardware store to use in my sauna?"
A."Light fixtures used in saunas must be vapor-proof and certified for use in a sauna environment. If your fixture doesn't meet these criteria, don't use it."

Q. "How long does it take for a sauna to reach operating temperature?"
A. "If you have insulated your walls and ceiling carefully, your sauna room should reach operating temperature in about 15 minutes. We recommend you close any vents and doors during the warm-up period. Other factors such as opening the sauna door, glass windows, ceramic tile may extend this time slightly."

Q."Why do you recommend sauna benches be assembled upside-down?"
A."By doing this, you ensure all screw and nail heads are invisible and are not going to be in contact with your skin when you're using the sauna. You will get a skin burn if you touch a metal surface at sauna temperatures."

Q."I'm thinking of supplying my own cedar for benches and to line the sauna. What would you recommend?"
A."Knots in cedar can have the same effect as the screw heads I mentioned in question #5. Because we purchase clear cedar in such large quantities, it's more than likely we can supply cedar from our warehouses that is better quality and less expensive than what you can source locally. Plus our cedar is kiln-dried to our specifications to eliminate warping and shrinking in the sauna."

Q."I'm planning a commercial sauna for a recreation complex or commercial spa. What things should I be thinking about?"
A."Many state and/or county codes require special consideration for wheelchair accessibility. Check what requirements your area has for the width of the sauna door. Is glass a requirement in the sauna door for attendants to view sauna patrons? How much room is required in the sauna for wheelchair patrons to turn their chairs in the sauna room? Our sauna doors supplied with optional glass, are tempered on BOTH sides of the dual pane glass unit. Tempered glass is usually a requirement in commercial saunas."

Q."I notice your sauna kits are listed in increments of whole feet. What if my sauna room size is slightly different?"
A."We've listed these sizes because they are the most common, however if your sauna room is different than these sizes, we can accommodate these as well. In fact, we encourage you to fax us a sketch of your room (use pen please) and we'll do a scale drawing on our CAD system and send it back to you with our recommendations and pricing. Be sure to include your name, address, phone number as well as your email address."

Q."Why aren't your sauna heaters available in colors?"
A."Excellent question...heaters that come in different colors are made using a material such as prepainted steel or aluminum, a process that involves a substrate being sprayed with a colored paint. This construction material looks nice on building exteriors, etc. but is NOT a material that stands up well at sauna temperatures. Usually a prepainted sauna heater that looks nice in a brochure or website, will look drastically different after only a few months as moisture runs down the outside of the heater and oxidizes leaving an ugly residue etched into the prepainted steel. Furthermore, as the prepainted material separates from the underlying material, it leaves the subsurface exposed resulting in accelerated deterioration. Our heaters are finished in stainless steel which delivers long service and excellent durability."

Q."I'm confused about sauna information on the Internet. What is the difference between a "modular sauna" and a "sauna kit?"
A. "A modular sauna is a series of panels that have been pre-assembled at a factory and permit the erecting of a small sauna room in an hour or so. An electrician and electrical permit is still required to run and connect the supply wire to a modular sauna. With a modular sauna you are paying someone else to do most of the wall fabrication and usually the freight to ship a modular sauna is quite high. It's not uncommon for a modular sauna to cost 4 times the price of a sauna kit. Homecraft does not offer a modular sauna at this time.

Most modular saunas on the market today are insulated with foam in the panels. Our research and conversations with the laboratories of foam manufacturers confirms that "off-gassing" occurs in foams when subject to high temperatures. Until we are able to find a stable insulating product for modular walls, Homecraft won't sell a modular unit." 

"Modular" Sauna Advantages:

  • no framing skills required
  • faster assembly time
  • can be dis-assembled at a later date if desired

"Modular" Sauna Disadvantages:

  • significantly higher cost to purchase
  • significantly higher cost to ship
  • offers little or no flexibility of sauna layout, benching or sizes
  • usually insulated with foam, not a material recommended or stable at sauna temperatures.

A sauna kit is comprised of all necessary materials to line a framed wall that you will have constructed onsite. The cost of a sauna kit is much less than a modular room and allows more flexibility for size and configuration. The freight cost of shipping a sauna kit is much less than a modular room. A sauna kit is the most "cost effective" way of building your own sauna room. An electrician is still required to connect the heater to your electrical panel."

"Sauna Materials Kit" Advantages:

  • lower cost to purchase
  • lower cost to ship
  • affords greatest flexibility in planning and design
  • can be easily adapted for any changes onsite
  • looks more part of your overall design when built in an existing home or business
  • can easily add additional sauna lights, sound speakers, etc. onsite.

"Sauna Materials Kit" Disadvantages:

  • does require some, albeit simple, carpentry knowledge
  • once built, a sauna kit room is usually permanent

Q."Is a floor drain required in a sauna?"
A."No, any water applied to a sauna heater should be done using a ladle. This accomplishes 2 things. It keeps your hand away from rising steam preventing a possible steam burn, and secondly, it applies just the right amount of water that will turn to steam when it hits the rocks. If you are pouring so much water onto the heater so the floor is awash with water, it is doing no good in the sauna and is far too much. NOTE: use only potable water, NOT water from a swimming pool or hot tub which contains chlorine and is very corrosive as well as unhealthy."

General sauna instructions relating to heater size, wiring, insulation, etc

The following sauna information will help you use and choose your sauna equipment properly. It is designed to provide simple steps that will help you enjoy your sauna and receive the maximum benefit from it.

Wet Or Dry Saunas?....

Many people ask, "Is this a wet or dry sauna?... Can we have water on the heater rocks?"

The traditional-style sauna heaters installed in the US and Canada are tested and approved by their respective Standards bodies. In the United States this is usually U.L. (Underwriters Laboratories). In Canada the comparable agency is C.S.A. (Canadian Standards Association) and are approved for use with water. There are, however, some points to consider:

1. THE APPLICATION- Is the heater in a residential or commercial setting? The residential homeowner will usually look after his equipment and not abuse it, whereas in a public, commercial setting such as hotels, recreation centers, clubs, etc., equipment seems to suffer untold abuse. To avoid this, some public saunas have taken to posting signs such as, "THIS IS A DRY SAUNA - NO WATER ALLOWED". This is usually an attempt to discourage the use of any water, whatsoever.

2. AMOUNT OF WATER TO USE- Water must be used in small amounts when the rocks are hot. Using large amounts of water will cause unnecessary spillage onto the floor, but more important, will cause a premature breakdown of the heater elements. "More is not better!"

3. HOW TO APPLY THE WATER- CAUTION! Water must NEVER be applied by pouring from a cup, bucket or similar containter. The rising steam can burn your skin. Using a ladle or spray bottle will give good control when applying the water in moderate amounts, and keep your hands a safe distance from the rising steam.

Determining the size of the Heater & Room....

Most sauna websites on the Internet provide a chart or graph for determining the appropriate heater for any given room size. Refer to the ĎSAUNA HEATING AND ELECTRICAL SPECIFICATIONí chart for the appropriate heater and control once you know the cubic footage of your planned room.

1. ROOM SIZE- Often prospective sauna customers are vague when describing what room size they really want and initially give a room size larger than the capacity of the largest residential heater, thinking "bigger is better".

Common residential room sizes are 5' x 6' x 7' high; 6' x 6' x 7' high; and 7í x 6í x 7' high, but many other sizes are available, as well as custom configurations.

2. CEILING HEIGHT- Residential sauna ceiling heights are normally reduced to 6-1/2í (minimum) or 7 ft. (maximum) to lessen the cubic area of the room so that a smaller heater can be used. More importantly, because heat rises, the lower ceiling allows the sauna bather to sit in the hotter temperature area when sitting on the top bench.

The temperature measured 12" down from the ceiling can vary up to 18 degrees F (10 degrees C)! Customers with 8' ceilings often complain that the sauna is too cold. This is because the hotter air is "pooling" above their heads. Another factor is a higher ceiling will often lead to heater operation problems as the heater struggles to achieve operating temperature, but with a higher ceiling than the design specs called for.

The maximum room temperature that a room is allowed to reach by U.L / C.S.A. standards is 194F, (90 C) where the thermostat bulb senses the temperature above the heater. This gives an average temperature of 176F to 185F (80C - 85C) where the sauna bather sits on the upper bench.

Components to make a sauna room....

Insulation & Vapor Barrier....

The required minimum insulation for a sauna room is R-12 of fiberglass batts for walls and ceilings. The aluminum foil vapor barrier is necessary for sauna rooms because it keeps itís integrity. Polyethylene vapor barriers deteriorate within the upper areas of the sauna room because of the high room temperatures, therefore it is not acceptable.

One further note; the time and care taken during insulating and applying the vapor barrier will pay dividends when the room is finished. Sloppily applied insulation will often result in the heater cycling more frequently to maintain the desired temperature in the room. Donít be impatient during this step, youíll be glad later on !!

The reflective vapor barrier also has an insulation value of R-2.64. These vapor barriers are applied with the reflective side facing into the room. Good results have been achieved by sealing all vapor barrier joints with tape for airtightness. Do not stretch the vapor barrier tight, rather drape it loosely between studs and in the corners. The vapor barrier will shrink as itís exposed to heat....allow for this when applying. Also do not get enthusiastic when stapling, rather keep perforations through the vapor barrier to a minimum.

Ventilation of Sauna Rooms....

Ventilation is an important part of any sauna room. If there is no ventilation the sauna room will feel stuffy and confining, (not to mention downright uncomfortable). Much has been written and many opinions offered on how a sauna room should be vented.

Intake Air

One option for incoming air is an non-adjustable intake vent directly below the sauna heater, installed through the wall. An alternative is by using sauna doors which are designed with a 1/2" to 3/4" airspace between the bottom of the sauna door and the floor. Using the space under the door eliminates having to cut a hole in the sauna wall under the heater.

This space allows incoming air to move along at floor level, over to the heater where it is heater and rises to the ceiling. Upper vents are not available in doors with glass panels.

Exhaust Air

One option is using an adjustable exhaust vent on the opposite wall around the same level as the top bench, positioned diagonally to the intake vent. This way fresh air is drawn in by convection and forced to the ceiling. Stale air is in turn exhausted. Never over-ventilate, or exhaust air too close to the ceiling as too much hot air will escape causing the heater to overwork resulting in nuisance tripping of the high limit switch. With the adjustable doors on wall vent kits you can control the airflow while laying on the top sauna bench.

When using a through-wall vent kit, make sure you frame an opening that the vent will fit into. The framing will prevent the hot, humid sauna air entering into the wall cavity.

Some standard vented doors have an adjustable exhaust vent is already installed, located near the top of the door so you donít need a through-wall exhaust vent.

Electrical Hookup....

Because the sauna heater is sized according to the size of the room, the wire and breaker required is determined by the amperage and volts of the sauna heater. Refer to the wiring schematic included with your heater/control for the wire size and breaker capacity requirements for your heater.

There have been problems when the electrician has installed too light a gauge of wire, making home owners very irritated when the proper wire size to supply the heater has to be re-pulled through finished walls.

Take note in the installation instructions regarding the position of the sensor bulb of the sauna thermostat! Some thermostats have a copper capillary tube attached. This tube cannot be disconnected. Neither should it be kinked or bend sharply. This will result in false readings by the thermostat.

Installers must ensure that the sauna control is placed close enough for the sensor bulb to be installed in the right position inside the sauna room. Positioning the sensor bulb anywhere other than specified by the manufacturer will result in operational problems with the heater.

G.F.I. (Ground Fault Interrupt) Breakers....

Customers are advised to avoid installing the sauna control within the range of a pool or spa etc., where a G.F.I. circuit is required. G.F.I. breakers and sauna heaters do not always get along well together, and there could be "nuisance" tripping of the breaker. As well, some breaker systems are very costly.

Where a G.F.I. breaker is required, electricians use an alternative system where the contactor and control circuit are wired to a 120V G.F.I. breaker. The sauna heater having its own circuit, does not need to be on a G.F.I..

Replacement Heaters....

Where the problems arise is when a pre-1982 sauna heater has to be replaced. UL and C.S.A. standards changed dramatically in 1982. The most significant change to the standard was (1) the reduction in allowable room temperature. Maximum allowable room temperature went from 248F (120C) down to 194F (90C), and (2) the introduction of a manually reset high-temperature limiting switch within the sauna heater. The high limit switch is intended to shut down the heater under any abnormal operating condition. As of 1982, a one-hour timer is mandatory on all residential sauna controls.



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