Thermo Aspen Sauna Wall Panel STS4 15 x 120mm x 1.8m Pack of 18 for Horizontal Cladding

This Thermo Aspen sauna wall panel is premium A grade Thermo Aspen, a tongue and groove wall and ceiling panel with a modern softline STS4 profile, machined for sauna use and supplied in a pack of 18 lengths of 15 x 120mm x 1.8m. Each pack gives 32.4 linear metres and covers approximately 3.56 square metres of wall or ceiling (approx. 110mm visible cover width). The 1.8m length is ideal for horizontal cladding, spanning vertical battens with little waste and easy to handle in a small sauna, cabin, bathroom or garden room.

Why Thermo Aspen for saunas

Thermo Aspen is aspen that has been heat treated at high temperature. This gives it a warm, even brown colour right through the board and makes it more stable and resistant to moisture, while keeping aspen's resin-free, splinter-free and cool-to-touch qualities. It is kiln dried and planed smooth, ready to install.

How much do I need?

Measure the wall and ceiling area in square metres and add about 10% for cutting waste. One pack covers approximately 3.56m², so a 2m x 2m sauna with 2.1m high walls and ceiling (about 21m²) needs around 7 packs.

Horizontal cladding installation

Fix battens vertically at 400 to 600mm centres over a foil vapour barrier, then fit the panels horizontally with the tongue facing up. Each 1.8m length spans the battens with no wastage, and joints can be staggered on a batten. Horizontal boards make a room look wider and give a clean, modern Scandinavian look. Fix with concealed sauna nails or clips through the tongue.

Finishing and care

Leave untreated inside the hot room, or finish with a sauna wax or paraffin oil made for saunas. Never use varnish or ordinary paint inside a sauna. Wipe benches after use and let the sauna dry out with the door open.

Specification

Species	Thermo Aspen (Populus tremula (thermally modified))
Profile	Sauna Wall Panel STS4 - tongue and groove wall and ceiling panel with a modern softline STS4 profile
Size	15 x 120mm x 1.8m
Pack	18 lengths (32.4 linear metres)
Coverage	Approx. 3.56m² per pack
Grade	Premium A grade, knot-free and resin-free
Colour	Natural warm brown
Treatment	Thermally modified, kiln dried
Approx. pack weight	24.4kg
SKU	TF-SA-TAS-STS4-15x120-1800-P18
Barcode (GTIN-13)	5061137590920

Frequently asked questions

Can I use this timber inside the hot room?

Yes. Thermo Aspen is a traditional sauna timber with low heat conductivity, so it stays comfortable to touch, and it is resin-free so it will not weep sap in the heat.

Do I need to treat it?

No. It can be left untreated. If you want extra protection, use only a sauna wax or paraffin oil made for saunas, never varnish or ordinary paint.

Can I fit it horizontally?

Yes. 1.8m lengths are ideal for horizontal cladding across vertical battens at 400 to 600mm centres.

Is delivery included?

Yes. The price includes VAT and delivery, with no extra charges at checkout.

Also available in 1.5m (pack of 24), 2.1m (pack of 18), 2.4m (pack of 12). Browse all sauna timber, sauna wall panels and sauna bench boards.

All prices include VAT and delivery.