Current Thermory Square No. 45 Installation Guide – Rev. 2026-05-18
Current manufacturer No. 45 / K140 assembly guide, visibly revised 2026-05-18.
The Thermory Square No. 45 is a compact outdoor sauna kit for one to two people. Its rounded square shell, glass front and solid wooden rear wall create a private sauna space with a small footprint. A rain jacket is included.
Specifications
| Exterior (W × D × H) | 52.76″ × 57.09″ × 87.00″ |
|---|---|
| Interior (W × D × H) | 47.64″ × 44.09″ × 76.77″ |
| Door (W × H) | 24.41″ × 73.03″ |
| Occupancy | 1–2 people |
| Shell material | Thermally modified Nordic spruce |
| Wall / board thickness | 1.57″ (manufacturer specification) |
| Nominal volume | 98 cu. ft. (manufacturer specification) |
| Front / rear | Glass front with door / solid wooden rear wall |
| Porch | No porch |
Dimensions follow Thermory’s May 2026 No. 45 dimension drawing. Thermory describes the drawing’s measurements as rounded, informative values.
Design & Materials
The shell is made from thermally modified Nordic spruce. Thermal modification uses heat and steam to improve wood stability and decay resistance. The interior includes a rear seat, side bench, backrest, floor grids and a movable step bench.
The shell is a single layer of wood. Thermory’s 25-year rot-resistance statement describes the thermally modified wood; it is not a 25-year warranty on the complete sauna.
Heater Options
Thermory lists the Homecraft Revive Slim 5 kW with a TKE2-2 indoor/outdoor control for the No. 45. Sauna Marketplace also offers a Harvia KIP 6 kW option. Choose the package in the product options to see what it includes.
Heater placement, clearances, ventilation and electrical work must follow the selected heater’s installation instructions. The Revive Slim manual specifies 42″ above a 36″ heater (78″ total), while the No. 45 drawing lists 76.77″ inside; the shielded Thermory package needs its applicable installation instructions confirmed before installation.
Assembly & Placement
The kit includes pre-cut, pre-milled wooden components and an assembly guide. Thermory recommends two people; assembly typically takes about a day, depending on experience. Electrical installation requires a qualified electrician.
Install the sauna on a stable, level base that supports its weight, with the cradles raised clear of wet ground and space for maintenance. Follow the guide for wood treatment, roof-cover fitting, band tightening and snow removal.
The No. 45 guide shows a low ventilation opening through the rear panel, covered by an exterior grille. It does not show a wall duct rising to a high outlet. Additional ventilation requirements depend on the selected heater.
Included Components
Assembly guide; two cradles; center, body and roof-closing staves; rear wall panels; glass front panels; door, handle and moldings; wooden trims; rear and side benches with supports; backrest; floor grids and movable step bench; metal bands; seals, fasteners and assembly accessories; rain jacket and securing slats. See the exact-model parts list for the complete inventory.
Warranty & Delivery
Thermory provides a two-year limited warranty for the initial buyer, subject to its warranty terms and exclusions. Heaters, electrical components and glass are excluded from that Thermory warranty; their applicable coverage is separate.
Sauna Marketplace ships this kit by palletized LTL freight with curbside lift-gate delivery. Ask about the Sauna Marketplace Builder Network if you would like help arranging assembly.
Prebuilt
Sauna Brushes
Vents