How We Built a Kids' Climbing Wall from Reclaimed Wood and 3D Printed Holds

A year ago, I built a simple tree structure for my kids to reach their little cabin. It worked, but let's be honest — climbing a ladder gets boring fast. So this time, we decided to level things up and build a proper climbing wall against the treehouse, complete with its own entry hatch.

This build combines two things I love: reclaimed materials and 3D printing. Almost everything used here — apart from a few structural essentials — came from pallets and wood we found in the street. The climbing holds, on the other hand, were designed and 3D printed from scratch. Here's how the whole project came together.

Materials: Mostly Reclaimed, A Few Exceptions

I kept the shopping list short on purpose. The only items I actually bought were:

• Heat-treated beams for the main structure

• Galvanized ground supports, since these would be going directly into the soil

Everything else — the boards, the bracing, the planks — came from reclaimed wood, mostly pallets I'd been breaking down over the previous weeks and months, plus wood picked up off the street. It's a good reminder that a sturdy, good-looking build doesn't have to start with a trip to the lumber yard.

Framing the Structure

The frame started with the two main beams, spaced roughly 74 cm apart. I built the structure directly against the table so I could get an accurate sense of proportions and angles as I went — a handy trick if you're working without a fixed blueprint.

For the horizontal supports, I measured 40 cm down from the top for the first cross piece, then 120 cm for the second, keeping everything centered. To keep the joinery consistent, I used a domino joiner: cutting the first set of holes high up using one reference surface, then moving the domino down to cut a second, lower set of holes using the same top reference. This kept every joint aligned even across multiple boards.

Once the domino holes were cut, I raised the fence slightly to punch a set of secondary holes all at the same depth — not a perfect solution, but a practical one for adding extra strength without redoing all the joinery from scratch.

Each joint got a generous amount of wood glue before being ratchet-strapped tight. While the glue cured, I added metal brackets across the frame for extra rigidity. Was it overkill for a kids' climbing wall? Probably. But since this structure lives outdoors permanently, I'd rather over-build than deal with a wobbly wall a year down the line.

Setting the Angle and Anchoring It

To get a comfortable climbing angle for a child — steep enough to add a bit of challenge, but not intimidating — I set the frame at a slight incline against the treehouse. Two additional pieces of wood were added at the base, not for structural support exactly, but to tie the wall into the rest of the cabin structure for cohesion.

With the angle locked in, it was time to anchor the frame into the ground. I mixed concrete for the base, poured it around the galvanized supports, and didn't worry too much about how neat it looked — the plan was always to bury it under soil once it cured. If you want your concrete base visible instead of buried, you can build a simple wooden form to pour into, or repurpose a bucket with the bottom cut off (flipped upside down) to create a clean cone shape.

After leaving the concrete to cure overnight, everything was rock solid and ready for the next stage.

Installing the Reclaimed Wood Planks

With the frame anchored, I moved on to the climbing surface itself: individual planks pulled from pallets I'd broken down over the previous weeks. Each plank got installed, then stress-tested by jumping on it with my full body weight before moving to the next one — a simple but effective way to catch weak spots before a kid ever sets foot on the wall.

I intentionally left extra space at the top since I hadn't finalized how the entry hatch into the cabin would work. Once all the planks were up, I trimmed everything flush for a clean finish, ready for the climbing holds to go in.

Designing and 3D Printing the Climbing Holds

This is where the project got a little experimental. I designed and 3D printed three different styles of climbing holds using a Bambu Lab P1S printer.

A few notes on the print process and material choices:

• Filament drying mattered a lot. I used PETG and ASA, both of which are highly sensitive to moisture. Getting them properly dried before printing — with help from the AMS 2 and AMS HT — was essential for clean, reliable prints.

• PETG-CF was chosen for holds that needed maximum strength and durability.

• ASA was used for holds that needed better outdoor resistance, even though this particular wall doesn't get much direct sunlight.

• Infill was set to 30–35%, which gave the holds plenty of structural strength. My main concern wasn't strength so much as delamination over time, which is why every hold design includes at least two mounting points for added security.

I know 3D printed climbing holds are a controversial choice for some people, and honestly, I share some of those concerns myself — mainly around long-term durability outdoors. Before letting my kids near them, I tested every single hold with my own body weight first. My plan going forward is to check them every three to six months to monitor how they're holding up, since this is something I take seriously when it comes to my kids' safety.

Placing the Holds

This was easily the most fun part of the whole build — and my kids got to help decide where each hold went. We aimed for a route with a mix of difficulty: some holds close together for an easier climb, and others, like the black ones, positioned to be more challenging.

Once we had a good spread of holds at varying difficulty levels, it was time for the real test: my kids climbing the wall themselves. Watching them make it to the top — and then figure out how to climb back down, which turned out to be the harder part — made the whole project worth it.

Finishing Touches: The Entry Hatch

With the climbing wall functional, the last step was building the entry hatch so that once a kid reaches the top, they can climb straight into the treehouse cabin — giving them their own dedicated "kid entrance" alongside the main adult entrance.

Final Thoughts

I'm genuinely happy with how this turned out. My kids have been using the wall constantly since it was finished, and there's something really satisfying about building them a space using almost entirely reclaimed materials, topped off with custom 3D printed holds designed specifically for them.

If you're thinking about a similar build, my biggest takeaways are: don't underestimate the strength of reclaimed pallet wood when it's assembled properly, over-build your joinery if the structure lives outdoors, and if you go the 3D printed route for climbing holds, test them thoroughly yourself before your kids ever touch them — and keep checking in on them over time.

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Have you built something similar with reclaimed wood or 3D printed parts? I'd love to hear how it turned out — drop a comment below.