Natural Alder (Saunawood) Bench Boards – 120×27 mm – 2400 mm (8 ft.)

Natural Alder (Saunawood) Bench Boards

At 120 mm wide, these are the bench boards to choose when you want the most comfortable seat with the least fuss — a broad, smooth surface that covers a bench frame faster and with fewer gaps than narrower boards. And because the bench is the one place your skin stays in constant contact, alder is the right timber for it: it carries heat poorly, so the seat stays comfortable even at full sauna temperature. They’re milled from A-grade, knot-free, low-splinter alder, FSC-certified and stocked in our yard for delivery across Ireland.

Why Alder?

European alder (Alnus glutinosa) is the traditional Nordic bench timber for two reasons that matter most exactly where you sit. First, it’s effectively resin-free, so it won’t weep sticky pitch or spit hot droplets onto bare skin as the room heats — the failing that rules out ordinary pine and spruce for benching. Second, its fine, even grain and A-grade selection mean a genuinely low risk of splinters on the surface you’re in direct contact with.

Add alder’s low density, which keeps the seat gentle rather than scorching, and a warm honey tone that deepens with every session, and you have a bench that’s as kind to sit on as it is good to look at.

Installation guidance

Building a sauna bench is more approachable than it looks, and the wider board makes it quicker still — fewer pieces to cut and fix to span the same seat. Run the boards along the bench frame and leave a small, even gap of around 5 mm between each one so air moves freely and water drains rather than pooling on the seat.

Fix from underneath with stainless steel screws wherever you can, keeping fixings out of direct skin contact; if you must fix from above, counterbore and plug so no hot metal sits proud of the surface. Order your bench boards and wall cladding together so they come from the same batch, since alder colour varies between batches, and allow around 15% for cutting waste.

Finishing & maintenance

You have two good options with alder benching, and there’s no wrong answer. The natural route — leaving the boards bare to silver gently with steam and time — is how most Finnish saunas finish their benches, and it asks nothing of you beyond letting the wood breathe. The treated route — wiping the boards with a dedicated paraffin-based sauna oil — is the one most of our customers choose for benching specifically, because it shrugs off sweat and body oils and keeps the wider seat easy to wipe clean. Never use ordinary varnish, lacquer, decking oil or exterior wood stain on a sauna bench: they seal the surface, grow uncomfortably hot, and release fumes when warmed. Whichever route you choose, clean with nothing more than a damp cloth and mild soap, then let the bench dry fully between uses.