Natural Alder (Saunawood) Bench Boards – 89×27 mm – 3050 mm (10 ft.)

Natural Alder (Saunawood) Bench Boards

The bench is the one surface in a sauna your skin never leaves, so it’s the one place you can’t compromise — and Natural Alder is the timber that gets it right. Because alder carries heat poorly, these boards stay comfortable to sit on even when the stove has the room at full temperature, so you settle in rather than perch on the edge. They’re milled from A-grade, knot-free alder that’s specifically low-splinter, 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, because the boards do the hard part: their rounded, knot-free faces give you a comfortable seat with no edges to dress. Run the boards along the bench frame and fix them with a small, even gap between each one — around 5 mm — 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 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.