Canadian Woodworking

Build an Indoor Bouldering Wall for Kids

Author: Jennifer Ball
Photos: Colin O'Conner
Illustration: James Provost
Published: February March 2014

Kids love to climb. Unfortunately, for most jumpy parents, kids often want to do it in the most dangerous places – like from rolling-desk-chair to top-of-fridge. In just one weekend, this fun project can channel those vertical compulsions somewhere a little safer.


For those of us city-dwellers with no grassy backyards and only occasional access to parks, it’s often an exercise in desperate creativity to get kids to burn off a little steam. An indoor bouldering wall can be a great, safe addition to any playroom, and it’s a project anyone with intermediate carpentry skills can whip off in just a weekend.

There are lots of advantages to installing an indoor bouldering wall. For one thing, bouldering requires no set-up or clean-up – it’s always ready for a five- or 25-minute energy burn. Bouldering teaches kids balance and coordination, and the mental challenge means that they’ll hardly notice they are “working out.” Plus, bouldering walls are fun: different-coloured holds and surfaces can offer opportunities for a variety of cooperative games (follow the leader, only-touch-the-red-holds, etc.).

Bouldering walls are also relatively safe. Yes, it’s true that bouldering is similar to rock climbing, but the objective here is to safely move side to side, instead of up. Holds can be placed mere inches off the ground so that injury from falls is limited. A simple bouldering wall can be assembled and installed in just a few days (if you send the kids to the grandparents, that is).

Choose a Wall
 A great bouldering wall doesn’t have to be high, especially when the climbers are young. However, if you do have an area with high ceilings it will offer more height, and potentially more challenge, down the road.

Find the Studs
 Start off by finding the studs in the area where the bouldering wall will be installed. If they are not as solid as they could be, it’s safest to either select a different location for the bouldering wall or strengthen the studs somehow.

Strap the Wall
Run 2x4s horizontally, fixing them to the existing studs. Don’t skimp on number or length of screws, as this is the foundation of the bouldering wall.

Lots of T-Nuts
Once the 1/2" diameter holes are drilled, hammer in the T-nuts from the back of the wall. The flange on the back of the T-nut will not come through the hole. Make sure all the holes get a T-nut.

Install the Wall
 Working from the bottom up, the panels are fastened to the wall. For a stable bouldering wall the horizontal joints should overlap the 2x4 strapping.

 Before driving the screws through the wall, use a counter-sink to ensure no splitting occurs, and to keep the surface of the wall free from obstructions.

Install the Holds
 Young kids can’t reach very far, so keep the holds low and close together. There’s lots of time to use the high sections of the wall in the future. Also notice the crash mat on the ground ‘just in case’. The higher the climbers go, the thicker the mats should be.

Wood Holds
 Making your own wood holds with a bandsaw, chisel, rasp and other hand tools is fun and cost-effective. You also get exactly the size and shape you want. Just be sure to ease all the sharp edges.

Evaluate your playroom

The first step to building a bouldering wall is ensuring the wall will be adequately safe and supported. We knew we would be installing a wall before we drywalled, so we rein­forced our studs by bolting them to the concrete-block walls of our playroom extension. Many would probably say this was overkill. If you aren’t inclined to remove your drywall (and if you don’t have concrete walls behind your studs), simply use a stud finder to verify that your studs are 16 inches apart or less. That should do the trick. It goes without saying that if you aren’t positive your studs are in good shape, it’s probably not a good idea to proceed with this project.

Cut and prep the plywood

Next, figure out the most cost-efficient use of plywood based on the size of the wall you are building. Cut them to size so they will fit in place on the wall. Cut-outs for vents or electri­cal outlets may be required. We cut four 4×8 sheets of 5/8 inch tongue-and-groove, smooth-one-side plywood.

We decided to use a giant world map printed on wallpaper ( as the surface of our wall. Once we cut the plywood panels to the right size, wallpapering them was the next step. If you choose to go this route, you should know that traditional wallpaper paste does not adhere to wood – the wood fibres absorb the water in the paste and the paper will just peel right off as it dries. For that reason, after a good sanding, we gave the plywood a coat of Shur Wall-Size before using a regular cellulose paste to adhere the wallpaper.
Other options for wall surfaces include a simple water-based urethane or a gritty textured paint (Metolius makes a nice textured paint specifically for climbing walls). Some people choose to leave the plywood bare for a pared-down look. If you’re one of these minimalists, a solid sanding is a good idea to minimize splin­ters in soft little hands.

Reinforce the wall

Most bouldering holds require a spe­cialized type of fastener called a T-nut. Typically, the bolts that fasten your holds in place will extend through the plywood and the T-nuts. If plywood panels are installed directly over an existing wall, the bolts may dig into the drywall. For this reason, we chose to build a frame to set the bouldering wall away from the drywall. That way, when we choose to remove the wall, our drywall won’t be poked full of holes.

Our frame consisted of five lengths of 2×4 strapping, set horizontally and screwed into each stud through the dry­wall, and spaced roughly two feet apart. The tongue and groove plywood sec­tions are then screwed into the strapping, making sure the strapping overlaps any horizontal joints. Jeff Mann, an outdoor skills facilitator with lots of experi­ence building climbing walls, points out that if any of your T-nuts end up on a stud, or over the strapping, a 3/8″ drill bit through the T-nut will open up enough of a hole to get a bolt in.

Drill holes and install T-Nuts

Grab a drill and a 1/2″ bit; here’s when you turn your lovely smooth plywood panels into Swiss cheese. Some people prefer to drill holes in a grid pattern like pegboard, while others like to drill them randomly. Mann suggests drilling your plywood with the sheets stacked on top of each other and clamped together. “This helps prevent blow out on the back and saves time and energy,” he points out.

As you drill, think about your climb­ers. You may want to densely position the holes and offer lots of options on the lower panels. Also remember that little kids’ arms and legs don’t reach very far.
The T-nuts are then hammered into the 1/2″ holes and have a serrated flange that bites into the wood and prevents the nut from spinning. Later, the bolts that you send through the holds will screw into the hollow barrel of the T-nuts. That’s why all the T-nuts must be hammered into the backside of your boul­dering wall.

Good bouldering walls are modu­lar, meaning the holds can be moved around when one configuration gets a little boring. Therefore, all the potential holes must be drilled and all the T-Nuts must be installed before the walls go up. Once the walls are up, you won’t be able to install any more T-Nuts and you are committed to the number and arrange­ment of holes.

Once you’re sure you’ve hammered in all your T-Nuts, flip your plywood over and take care of any splinters of wood that may have pushed through. Screw the panels onto the 2×4 strapping, start­ing at the bottom and working your way up. Counter-sink the holes so the surface is free of any obstructions.

Finish the edges of the climbing wall with quarter round or trim if you want a cleaner look. Once the panels were up, we threw on a few coats of protective water-based urethane. Who’s kidding who, though – it’s just a matter of time before someone takes a Sharpie and scribbles all over this gorgeous map. I guess it’s just like the first scratch on a new car … once it’s over with, we can all relax.

Install your climbing holds

Once the plywood panels have been mounted, the next (and most fun) step is to install your holds. We bought our holds second-hand from a climbing gym that was being dis­mantled, but most outdoor stores carry a wide selection of colours, shapes, and sizes. Because most of our climbers are tiny, we chose fairly big, easy holds and we placed them near the ground and close together. Think about which holds suit feet and which will challenge hands, and place them accordingly.

Mann reminds bouldering wall builders that “there are cool specialty holds available which hold tennis balls and hula hoops. Pretty fun!” You can experiment with any configura­tion you like, but it’s a good idea to check your holds every now and then to see if they are spinning. Occasionally, T-nuts can loosen.

Think About Safety

Before you set your little climbers loose on the wall, be sure to consider a safe fall zone. This means, of course, clearing the area of toys – nobody wants to land butt-first on a sharp piece of Lego.

You will also need to think about a mat or crash pad. Because our holds were so close to the ground, we could get away with some 3-1/2″ dense foam gym-style mats. For bouldering walls that send climbers more than one or two feet off the ground, a dense foam mat combined with a fluffy padding, such as a commercially available bouldering pad (or simply an old mattress), are recommended. The fall zone should extend several feet from the base of your wall owing to the fact that often climbers stumble back before falling.

While climbing does come naturally to many kids, others will need some time to warm up to the crazy new apparatus that has taken over their space. Many kids will need hands-on, contact spotting at first. “Spotting is a good practice to encourage,” says Mann, “especially for novice or visiting climbers. Focus on cushioning not catching. The idea is to guide the falling climber safely on to the mat, not to put the spotter in harm’s way.” “Practice” falling can show poten­tial climbers that wiping out on a mat doesn’t have to hurt.

We’ve noticed that most of the safety issues involve multi­ple kids clambering on the wall at once. A “party” atmosphere will, of course, require close supervision.
The added bonus of a bouldering wall? Adults can challenge themselves too. Once you’ve installed your wall with your low, low holds, try making your way from one side to the other without letting your rear end touch the ground. It’s not easy!

Hold On!

It’s not only possible, but it’s also fun to make your own holds out of wood, although there are certain characteristics you will want to keep in mind. In general, wood holds are best used down low, where feet are going to touch them, but larger wood holds can easily be incorporated into your new wall with a common sense approach. And if you put your wall up, only to realize you don’t have enough T-nuts in place, you can always attach wood holds to directly to the surface of the bouldering wall.

Strength – Holds will have to withstand a fair bit of torque if someone over 100 lb. is going to hang off it. Hardwood is a great place to start, especially if you want to make the holds small or with thinner grips. The last thing you want to have happen is for a hold to break while someone is grasping it. Also take woods grain into consideration; flat sawn and non-porous woods are generally less likely to break during use.

Texture – In the great outdoors all rock has a bit of texture, which helps climbers gain grip. Roughly sawn wood starts off with a bit of texture, but it quickly disappears after being used; general use smooths the surface and sweaty, greasy hands add a lubri­cant, making the holds extra-difficult to hang onto. Adding texture with hand tools is a good start, but the more texture there is, the better things are. In the past I have covered the surface of the hold with glue and liberally sprinkled sand over it to add texture. You could also spray or wipe many standard wood finishes on the holds, then immediately sprinkle lots of sand over the holds. Both options work very well. It’s also a good idea to add some texture to the backs of the holds so they are less likely to spin on the wall during use.

Sharp Edges – Climbing can be hard on the fingers, especially if the holds have sharp or steep-angled corners and edges; ten­dons and muscles in the fingers don’t do well under high pressure. Be sure to ease all sharp edges to reduce injuries.

Jennifer Ball - [email protected]

Jennifer is a teacher and mom who uses her wild, noisy, crowded home workshop as a serene escape from her wilder, noisier, and more crowded toddler-dominated living room.

1 comment

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  2. Hi, the wall looks amazing!
    Could you tell me the approximate dimensions of the wall? And how do you know if your wall will be long enough to allow for adequate bouldering?
    What did you use to trim/frame the wall? Thanks so much, such an inspiration!

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