The structural design of outdoor sauna rooms must fully consider weather resistance, thermal insulation, safety, and construction adaptability while meeting the requirements of high-temperature and high-humidity environments. The overall structure consists of a foundation support, main frame, enclosure system, internal structure, and supporting facilities. These components work together to create a stable, comfortable, and sustainably operating independent space.
The foundation and support structure are the cornerstone of the outdoor sauna room, primarily bearing the load and isolating it from ground moisture and pests. Common methods include cast-in-place concrete bases, precast concrete blocks, or anti-corrosion wood elevated platforms. Concrete bases offer excellent moisture resistance and load-bearing capacity, are suitable for various geological conditions, and can be secured to the main frame with pre-embedded anchors. Anti-corrosion wood elevated structures offer flexible construction, facilitate drainage and ventilation, and reduce the thermal bridging effect on the ground. In cold regions, the base needs to be designed to prevent frost heave, and insulation layers and moisture-proof membranes should be installed where necessary to ensure long-term structural stability.
The main frame determines the shape and stability of the sauna room. The mainstream materials include pressure-treated coniferous hardwoods (such as red cedar and Alaskan yellow cedar) and anodized aluminum alloy profiles. Solid wood frames have a warm feel, low thermal conductivity, which helps maintain indoor temperature, and their natural grain enhances visual appeal; however, they require strict control over moisture content and crack prevention. Aluminum alloy frames are lightweight, high-strength, and highly corrosion-resistant, requiring almost no maintenance, making them suitable for variable climates or high-humidity environments. Frame connections typically use mortise and tenon joints, bolt fastening, or specialized metal connectors to ensure overall rigidity and seismic performance.
The enclosure system includes walls and a roof, which must simultaneously meet requirements for waterproofing, insulation, ventilation, and weather resistance. Walls often consist of a double-layer structure: the inner layer is a sauna-specific panel (often made of high-quality spruce or red cedar), which is heat-resistant, easy to clean, and emits a natural fragrance; the outer layer is covered with waterproof board or weather-resistant synthetic materials, supplemented with UV-resistant coatings to resist aging caused by sun and rain. The wall cavity can be filled with mineral wool or polyurethane foam insulation to reduce heat loss and improve energy efficiency. The roof is generally sloped for drainage, covered with waterproof membrane or weather-resistant synthetic tiles on the outside, and has an inner insulation layer and protective panels, with ventilation openings to prevent internal steam condensation and structural dampness.
The internal structure is designed around functionality, including benches, backrests, heater bases, and ventilation systems. Benches are often tiered or parallel, made of whole or spliced high-temperature resistant wood, with smooth surfaces and appropriate slopes for ventilation. The heater base must be separated from the wooden structure by firebricks or steel plates to prevent ignition at high temperatures. The ventilation system consists of air inlets and outlets, their locations and areas calculated to ensure steam flow and temperature balance while preventing excessive heat loss.
Supporting facilities and safety structures include thermostats, lighting, chimneys, and electrical wiring. The thermostat system can be either embedded or remotely controlled depending on the heating method, ensuring convenient and safe operation. Lighting fixtures should be moisture-proof and high-temperature resistant, and powered by low voltage to prevent electric shock. Wood-burning stoves must have independent chimneys extending above the roof, made of stainless steel or high-temperature alloy, and equipped with rain caps and spark arresters to ensure smooth smoke exhaust and reduce the probability of fire. All electrical wiring should be laid in conduits and isolated from high-temperature areas, complying with outdoor electrical safety regulations.
In summary, the structural design of outdoor saunas is a systematic project integrating materials science, thermodynamics, and architectural engineering, requiring a balance between weather resistance, thermal performance, safety, and aesthetics. Reasonable structural selection and detailed treatment can not only extend the building's lifespan but also significantly improve user comfort and safety, providing a solid foundation for the sustainable operation of outdoor health and wellness spaces.
