DIY Sauna Bench Plans: Heights, Depths & Layouts
Detailed dimensions and plans for building comfortable, functional sauna benches.
Benches are where you spend your sauna session. Getting the dimensions right is critical for comfort, safety, and thermal performance. This guide provides exact dimensions and layouts for different sauna sizes.
Bench Height Above Floor
Sauna benches are arranged in tiers, with each tier getting higher. This creates a heat gradient — the highest bench is hottest.
- Lower bench: 16–20 inches above floor (coolest). Good for beginners.
- Upper bench: 40–48 inches below ceiling (hottest). For intense sessions.
- Optional third tier: 28–32 inches above floor (middle ground).
Vertical distance between tiers: 12–16 inches for comfortable stepping.
Bench Depth (Front to Back)
Depth determines how much space you have to lie down or stretch out.
- Minimum depth (sitting): 16 inches. Allows sitting but not lying.
- Comfortable depth (reclined): 24 inches. Lets you lie back or lean.
- Full-length lying: 30–36 inches. Lets you stretch out fully.
For most people, 24 inches is a good compromise.
Bench Width (Space Per Person)
- Minimum per person: 18 inches (tight, one person).
- Comfortable per person: 24–30 inches (allows movement and space).
- Generous spacing: 36 inches per person (spacious).
For a 6×8 sauna, a single 6-foot bench allows 2–3 people comfortably.
Bench Construction Details
Support structure: Angle-iron brackets bolted into wall studs, or wooden supports attached to frame.
Surface boards: Use 2×4 or 2×6 cedar/redwood. Space boards 1/2 inch apart for water drainage (never solid surface).
- Upper bench: 5 horizontal boards (2×4s) with 1/2" gaps = 24" depth
- Lower bench: 3 horizontal boards (2×4s) with 1/2" gaps = 16" depth
All boards must be securely fastened to prevent movement.
Fastening and Hardware
Use stainless steel or galvanized fasteners only (regular steel rusts).
- Bracket attachment: 3–4 inch bolts into studs (min. 16" spacing)
- Board-to-bracket: 1/4" x 3–4" bolts with washers and lock nuts
- Board-to-board: Stainless steel bolts or screws (avoid nails)
Standard Sauna Layouts
4×6 sauna (compact):
- Lower bench: One side, 4 feet long, 16" deep, 18" high
- Upper bench: Opposite side, 4 feet long, 24" deep, 42" high
- Capacity: 2 people comfortably
6×8 sauna (standard):
- Lower bench: One side, 6 feet long, 16" deep, 18" high
- Upper bench: Opposite side, 6 feet long, 24" deep, 42" high
- Third bench: Back wall, 4 feet long, 16" deep, 28" high (optional)
- Capacity: 4–6 people
8×10 sauna (large):
- Lower bench: One side, 8 feet long, 20" deep, 18" high
- Upper bench: Opposite side, 8 feet long, 24" deep, 42" high
- Middle bench: Back wall, 6 feet long, 18" deep, 30" high
- Capacity: 8–10 people
L-Shaped Bench Designs
Some saunas use L-shaped benches spanning two walls. This maximizes seating in confined spaces.
An L-shaped upper bench in a 6×8 sauna might run 4 feet along one wall, then 4 feet along the adjacent wall. This seats 3–4 people.
Challenge: Corner support brackets are complex. Requires heavy-duty brackets and careful engineering.
Material Selection
- Cedar: Most popular. Durable, pleasant smell, naturally rot-resistant. Expensive.
- Redwood: Similar to cedar. Good durability, slightly coarser feel.
- Aspen: Softer, budget-friendly. Less durable but acceptable if well-maintained.
Never use: Pressure-treated wood, oak, or softwoods like pine.
Spacing and Gaps
Always space bench boards with at least 1/2 inch gaps. This allows water to drain through rather than pooling. Without gaps, you encourage mold and rot.
Leave 1–2 inches of clearance between bench and adjacent walls for air circulation.