Build a DIY Climbing Cave in Your Attic or Garage

A DIY rock climbing wall

Lloyd Alter

My son loved to climb, and we used to often go to the local gyms. But they were too far to walk, and he didn't get to climb as often as he liked. I thought it really important that kids have diversions from the computer and the television, preferably ones that keep them active and fit. My son moved out a couple of years ago and while I thought the climbing wall was a real asset, I had to finally admit that it was time to move on. I took a few photos of us taking it down so that if anyone wants to do this in their attic or garage, they can learn from my mistakes.

Deciding the Shape

credit: Lloyd Alter

We live in a narrow three-story house with the kids' bedrooms at the top, essentially in the roof, so there are knee walls, a sloping section, and a flat section above. I wanted to build the wall in a way that minimized the number of holes I would have to make in the lath and plaster, because it is 100 years old and not in great shape. I designed the wall to work like an arch, without almost no fastening into the wall. All the weight rests on the floor.

Putting the Climbing Wall Together

credit: Lloyd Alter

The outward thrust of the arch was absorbed by a plate at the intersection of the roof joists and the knee wall, with just two screws to hold it in place while the arch was built on top.

credit: Lloyd Alter

It barely touches the ceiling; there is a 2x4 in there to keep the thing from wobbling but it isn't connected to the house at all.

credit: Library and archives of Canada

Everything is screwed together with Robertson square headed screws. They are a Canadian design that has been hugely popular since 1908, because they never slip and are so much faster. According to Archives Canada:

After badly cutting his hand while using a slot-headed screwdriver, Peter Lymburner Robertson invented the square-headed screwdriver and screw in 1908. He received the Canadian patent for his invention in 1909. A person could drive a screw more quickly with this new design and the screw was self-centering so only one hand was needed. On top of that, the driver fit more tightly in the screw's head, thereby reducing the chance of the screwdriver slipping out. The Robertson screw was a big hit! Industry loved it because it sped up production and resulted in less product damage. No one has been able to improve on this design in all the years that have followed!

Why they never caught on in the States is an interesting story, but they made assembly and disassembly far easier.

credit: Lloyd Alter

Studs in the knee wall and sloping sections were spaced at 16" oc; on the ceiling, where I really wanted to get a lot of screws and because the span was the longest, they are at 12" centers. The thing never moved an inch.

credit: Lloyd Alter

The wall panels were made from 4'x 4' 3/4" thick plywood. Holes were drilled on a 6x6 grid and T-nuts banged in the back.

credit: Lloyd Alter

2-1/2" screws held the panels to the framing. LOTS of screws, with more on the horizontal and sloping panels than the vertical ones. The ceiling had screws on 6" centers.

credit: Lloyd Alter

I put three layers of cheap underpad and a layer of carpet on the floor; you really didn't need a bed, it was so soft. 63 holds, six sheets of plywood and a pile of 2x4s cost less than an iPad and lasted a whole lot longer.

Why Build a Climbing Wall?

The wall got a lot of use over the years, and was known as the coolest kids' bedroom around. When I put it up for sale at the Mountain Equipment Coop members resale website for the price of the holds, I was surprised to find that it sold for my asking price in about half an hour, and that I got a dozen emails over the next two weeks that the ad stayed up. ( I clearly sold it too cheap but it found a very good home). Here is something that took two weekends to build. Since it was designed for disassembly we were able to take it apart in six hours and give someone else the opportunity to use it without a bit of waste. It provided a decade of fun and exercise, something we could do together, although I found it frustrating that I could never make it across the top and down the other side like Hugh could. It certainly was a better investment than any of the electronics I ever bought the kids.