If you’ve ever looked at a sauna and thought “something feels unfinished,” there’s a good chance the inside corners had nothing on them.
The ProSaunas Aspen 1×2 SI Inside Corner Trim covers the interior corner joint where two runs of wall cladding terminate. At 14mm thick (0.55″) and 30mm wide (1.18″), it sits in the corner and covers the raw edge of both wall faces cleanly. The SI profile is cut for inside (concave) corners: a flat back, a reveal that sits against each wall, and a clean face that reads as a deliberate design element rather than a cover-up. Milled in Estonia from natural aspen to match our cladding boards in color. Sold by the linear foot in 1 and 10 ft lengths.
Why Aspen
The same reason you clad the walls in aspen: pale, cool, resin-free, hypoallergenic. And matched. When the corner trim is in the same species as the wall, the eye reads the room as a single finished surface instead of a wall with something attached to the corner. Natural aspen is a softer wood, so this trim piece can dent if it takes a direct hit from a ladle or a bucket. In a corner that’s a low-probability event, but worth knowing.
Specifications
- SKU: PS-ASPEN-1X2-INSIDE-CORNER-TRIM-SI
- Species: Natural Aspen
- Profile: SI inside corner trim
- Thickness: 0.55″ (14mm)
- Width: 1.18″ (30mm)
- Available lengths: 1, 10 ft
- MAP: $1.61 per linear foot
- Milled in Estonia
Where it goes
Every inside (concave) corner in a clad sauna room. That’s typically 4 vertical corner runs plus any interior wall corners in a two-bench layout. For outside (convex) corners, the matching piece is the aspen 2×2 VA outside corner trim. Order both when you order your cladding: you’ll need them at the end of the job and they’re inexpensive to add to the order.
Shipping and samples
Sold by the linear foot. Flat $795 to the continental US, or free with a heater order. Free samples available: text your name and address to (844) 565-1113.
Call Ben² at (844) 565-1113 if you’d like to talk through the board count before you order.

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