If you’ve been following along, you know I’m deep in sauna world lately — and I’ve reached the stage where the details really start to make it feel finished. This week I’m sharing my DIY cedar duckboard and wood floor mat projects for our sauna and patio.
They might sound small, but they make a huge difference in how your sauna feels and functions. Duckboards (aka slatted wood floors) allow for drainage, airflow, and a clean, elevated feel underfoot — while the wood mat extends that warmth and texture to the patio, giving us a place to wipe any debris off our feet before entering the sauna.
The best part? Both can be made with the exact same process — the only difference is the pattern.
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Why You Need a Duckboard in Your Sauna
Before I started planning this space, I didn’t really think too much about the sauna floor… until we built it and I realized that indoor saunas don’t come with a floor. Since we have it outside on our covered patio, our sauna floor is the same stone tiles as the rest of the patio. This is perfect for the waterproof functionality, but less pleasant to step onto with our bare feet when getting in and out of the sauna.
A cedar duckboard solves two big issues:
- It keeps your feet off the cold floor (especially nice if you’re stepping in and out of a hot sauna)
- It allows airflow and drainage underneath, which keeps things dry and mold-free
It’s both a comfort and longevity upgrade — and it adds a custom, spa-level finish to your build.
The wood mat in front also gives us a place to wipe our feet before stepping inside, helping keep the sauna clean and reducing how often I need to sweep it out.
You can buy premade duckboards, but knowing how simple this build would be, I decided to DIY.
DIY Sauna Duckboard and Wood Mat
Two projects, one simple build.
DIY Cedar Duckboard Instructions
Materials Needed:
- 5x – 8ft 1×3 cedar boards
- 1” brad nails
- Brad nail gun
- Orbital sander
- Sandpaper (120 and 220 grit)
- Exterior-grade wood glue (optional for added stability)
- Non-toxic oil finish (I used tung oil)
- Optional: rubber feet (I skipped these)
1. Cut Your Cedar to Length
For one 24”x40” duckboard:
Cut 3 pieces to 40” long
Cut 14 pieces to 23.5” long
For the most efficient use of your boards, cut as follows:
- 3 boards to (1) 40” piece and (2) 23.5” pieces each
- 2 boards to (4) 23.5” pieces each
Custom sizing:
- Bottom pieces = full length of your duckboard (spaced about 1 ft apart for support).
- Top pieces = full width.
- To calculate quantity: divide your total length by board width + gap (e.g. 2.5” board + 0.375” gap = 2.875”).
- Example: 40” ÷ 2.875 = 13.9 → round to 14 boards
2. Sand The Boards Smooth
After cutting your boards, sand them smooth using 120 grit, followed by 220 grit. If needed, start with a coarser grit for rough spots. On the final sand, round over all edges to soften them since you’ll be walking barefoot on these!
3. Lay out your duckboard pattern
For your DIY duckboard, lay your top slats face down with 3/8” gaps between each. Place three bottom boards perpendicular to the slats — one at each end, one centered.
4. Nail it all together
Use 1-inch brad nails (perfect for two stacked ¾” boards) and use two nails per connection point, alternating angles slightly for a stronger hold. I nailed from the bottom side for a clean, seamless top — but top nailing works too if you don’t mind visible nail holes.
5. Seal (optional) and Enjoy your new DIY Duckboard!
Wipe everything down and allow to dry. If using inside your sauna, use a non-toxic sealer like tung oil, or skip it altogether like I chose to. Now it’s time to enjoy your DIY sauna duckboard!
DIY Woven Wood Mat
This one’s a little more complex than the duckboard — but still doable. If I didn’t have leftover slats from my DIY Hidden Closet, I probably would’ve purchased a ready-made mat (like this one). However, I couldn’t resist a good scrap-wood project, so I chose the satisfaction of the DIY option.
Looking back, I’d consider inverting the design (boards touching, gaps forming the woven texture). It’d be simpler and sturdier — but that’s not what I did!
Materials Needed:
- 1×2 boards of choice
- 1” brad nails
- Brad nail gun
- Orbital sander
- Sandpaper (120 and 220 grit)
- Exterior-grade wood glue (optional for added stability)
- Non-toxic oil finish (I used tung oil)
- Optional: rubber feet (I skipped these)
1. Cut the wood slats to size
The measurements for the woven mat pattern were slightly more tricky. I used leftover Ash wood scraps, but for the sake of this tutorial, I’ll use standard 1×2 boards.
My total mat size was 20” x 36”. Each set of boards must be calculated individually to account for the gaps at the top and bottom. I determined my total mat width by adding the total length boards plus gaps. This design is 14 boards in width, and 13 gaps, so (1.5 x 14) + (.25 x 13) = 24.25”
For each set of boards, I calculated inward, taking my total board width (1.5”) plus the gap (0.25”), then multiplied by two to account for either end, so 3.5”. I then subtracted 3.5 for each set. The math looked like this:
Length Cuts:
36” (2)
– 4” = 32.5” (2)
– 4” = 29” (2)
– 4” = 25.5” (2)
– 4” = 22” (2)
– 4” = 18.5” (4)
For Width Cuts:
24.25”
– 4” = 20.75” (2)
– 4” = 17.25” (2)
– 4” = 13.75” (2)
– 4” = 10.25” (2)
– 4” = 6.75” (2)
This pattern alternates to create the woven grid look.
2. Cut the Bottom Boards
For this complex design, the bottom boards were also a bit more complicated (another reason I would opt to connect all the wood boards if I make something like this again).
Bottom boards: Cut (3) boards to the total width (24.25”).
Sides: Cut (2) boards to the total length of just the side portions (around 8.75”). You can calculate this number by adding the total of the width boards plus gaps per side (5 x 1.75) or you can subtract your middle board width from your total width (36 – 18.5 = 17), and divide that number by 2.
Corners: These were the trickiest— I glued two boards together side-by-side, then cut angled edges to support the corners. To do this part, I measured the approximate length and cut my glued boards slightly long, and then I just took them and marked the angles for both the inner and outer edges.
3. Assemble and Finish
Follow the same sand, nail, and finish process described in Steps 2-5 above. Oil lightly if desired to protect the wood, and let everything dry before using. That’s it!
We’ve been using these for a while now and both have been excellent additions to our outdoor sauna setup. The DIY cedar duckboard makes stepping into the sauna so much more comfortable, and the woven wood mat adds warmth and texture to the patio — giving everything a cohesive, spa-worthy finish. If you’re working on your own sauna project, this is one of those easy wins that makes a big impact.
Be sure to check out the other projects and progress on the One Room Challenge blog!
