History of the Sauna
The oldest known saunas were pits dug in a slope in the ground and primarily used as dwellings in winter. The sauna featured a fireplace where stones were heated to a high temperature. Water was thrown over the hot stones to produce steam and to give a sensation of increased heat. This would raise the apparent temperature so high that people could take off their clothes.
The first Finnish saunas are now called savusaunas, or smoke saunas. These differed from present-day saunas in that they were heated by heating a pile of rocks called kiuas by burning large amounts of wood about 6 to 8 hours, and then letting the smoke out before enjoying the löyly, or sauna heat. A properly heated "savusauna" gives heat up to 12 hours. These are still used in present-day Finland by some enthusiasts, but usually only on special occasions such as Christmas, New Year's, Easter, and juhannus (Midsummer). As a result of the industrialrevolution, the sauna evolved to use a metal woodstove, or kiuas [ˈkiu.ɑs], with a chimney.
The first Finnish-American saunas were one-room structures made from squared logs, hewn and mortised at the ends and placed horizontally on top of each other, and with pitched roofs. This early type of bathhouse, called savusauna (smoke sauna), had no chimney; smoke from the wood fire encircled the walls, ceiling, and tiered benches, escaping through a small vent near the roof or through the door. The interior became black and fragrant from years of smoke.
The prehistoric sauna
The initial stages of sauna are to be found at Stone Age dwelling
sites among the remains of excavated hearths and fireplaces. The fireplaces were so called pit hearths, round-bottomed pits
up to a metre and larger in diameter and thirty centimetres deep, with two or three stones on the bottom. After heating the stones a tent, for example made of poles and hides, would have been erected over them.
The original sauna
During the time of hunters and fishermen, saunas were temporary
structures that were easy to build up. A conical hut like a tepee would have been suitable for this purpose. However, the high conical form was a poor design for a sauna, as the heat would rise to the top part. A lower hut of rods and branches connected with osier stakes would have been better, especially if it was partly sunk in the ground. Later, as mobility lost its importance the sauna was built deeper into the ground, and was thus protected from wind and frost and the floor was warmer and free from draught. It finally became a “underground cabin”, which had the function of both a dwelling and sauna. Stones were carried into the hut and they were heated red-hot, then water was thrown on the stones to produce the steam to heat the hut. The hut transformed in being used just a sauna with time. The walls the sauna would be of bare earth, sometimes lined with thin round logs or later on with halves of round logs. After mastering the log joining technique, people built two or three courses of logs on top of the sauna to protect it from weather.
The sauna had a low two-faced, saddle-back roof with a layer of birch-bark and turf on top. In the summertime long grass
would grow on the roof and hide the sauna in a green grassy hill. In the wintertime it would be completely covered in snow.
1. sketch of a prehistoric sauna, Erkki Helamaa
The origins of the Finnish sauna can be already found back
then: next to the door there stood a stone-laid stove and on
the rear or side wall was a bench made of split log, which was later replaced by a platform on posts. (Erkki Helamaa, Finnish Sauna 1994) These underground saunas remained in use for a long time: according to the observations of ethnographer Samuli Paulaharju made in 1907/1908 it remained the sauna of the poor as it was dug in the ground and thus little timber was needed. Underground saunas were used again during the Second World War in front line conditions. The saunas needed to
withstand enemy fire, and were thus built underground and
sturdy logs were used for walls and ceiling. The building style
is called “Korsuarkkitehtuuri”, which literally translates to “dugout architecture”.
The basic sauna
A major change in construction of Sauna building occurred through the discovery of new joining and hewing techniques.
This lead to corner-joining of logs instead of using upright hut constructions. Even though there are regional differences, there are also many similarities. Today this type of sauna is referred to as a smoke sauna. The building was a simple rectangular log structured building. The logs were stripped of bark, had a round shape and they were laid and joined in horizontal courses. In the intersection of the logs the joining technique was used: carving a notch in a log corresponding to the round form of the log, which was laid upon it. Later on the log was carved on both sides, which was developed into numerous even decorative interweaving techniques over time. Insulating the sauna walls was not a great concern, either it was forgotten or deliberately left out in the lower courses to establish better ventilation in the sauna.
The insulation materials used between the upper logs were clay and moss. Inside the building there was a stove covered with stones, which brought the building up to a high temperature. The special character of the sauna lies in the quality of the hot, dry air, which changes when water is being poured on the stove. Achieving the right balance of heat, humidity
and ventilation is the art of building a sauna. (Sauna - made in
Finland) In Western Finland the Sauna building was placed in the centre of the enclosed farmyard, in Eastern Finland outside
the yard, to take into account the fire safety, next to a well or
spring. These buildings had a shelter in front of the entrance for people to change. The shelter was built by driving stakes into the ground, with spruce branches hung from it during the winter. Commonly, also a gable roof above the entrance would be built and one side would be closed with timber
boards, stones or logs.
The first saunas were built on bare
ground, later on they were covered with stone slabs, loose
boards or poles which evolved eventually into floorboards and concrete floors. The roofing was made of birch-bark, peat,
straw, boards or beams. Shingled roofs were introduced in the 19th century. Also other building techniques were developed for sauna building: with the introduction of hewing straight carved logs were used. The former carved corner joint was followed by straight ones, which later lead to more ornamental and dovetail corners in the 1920’s and 30’s. After that time mostly vertical boards were used in urban sauna buildings and the log construction was abandoned. In the original saunas the ceiling and the roof were connected, so that the shape of the ceiling would depend on the design and shape of the roof. Later on the inside ceiling became an independent element.
The style of doors, the fittings like hinges and handles and
the overall simplicity of construction are characteristic for the sauna architecture. There was no hot water available in sauna in earlier times, only cold water for washing was being used, so one could go for a dip in the lake or sea or roll in the snow.
In the beginning of my research, I assumed that circular saunas are quite rare as one is mainly getting in contact with
the “L” shaped, or with the “U” shaped seating arrangement.
During closer examination I found out that there is in fact a number of saunas with circular seating arrangement and the stove in the centre. Nevertheless most of these saunas are just restricted to the circular seating arrangement. They keep the surrounding box shape and do not continue the circular shape
into the spatial environment with walls and roofing which are supporting the flow of the löyly as well. Already General Paavo Talvela (1897-1973) had the theory
that a fully balanced heat could only be achieved in a round
space. This circular “commanders sauna” was built in Nurmoila,
drawn by architect Aulis Kalman and gained public attention in Finland.