Climbing Wall Project

This page describes how we in Hjerm Climbing Club have extended our facilities and how you too can build a boulder wall. The initial work took place in my garage at home before being moved and installed at the climbing wall in sections. After making drawings of how the finished wall should look we decided to build the wall in sections, each 61cm wide (half a standard plywood sheet) by 3m high. Each section has its own form with overhanging sections, vertical sections and slabs. No two sections are the same.

For each section two identical frames are built from 57mm x 38mm timber, as shown above. The frames are glued and screwed together using PVA woodglue and 5 x 70mm countersunk screws. The two pictures above show building a single frame.

Above: Two complete frames ready for the plywood sheets to be cut to size and mounted. It is handy to cut the sheets you will need for the whole project in half longways before starting as you then have lengths of plywood ready in the correct width of 61cm, these then just need cutting to length as shown below. When cutting the sheets, use a circular saw and a straight-edge.

When cutting the plywood, saw each end of the plywood pieces with the correct angle and make sure you saw with the sheet upside down to get the cleanest edge on the front. Afterwards, before mounting the plywood on the frames, you need to drill holes and mount the M10 nuts for mounting climbing holds. Using a proper wood drill bit, drill 12mm holes in the sheets in a grid (for example in a grid of 12 x 10 cm). Make sure you leaving 8 cm all the way around to ensure that you do not mount the nuts in front of the frame. Mount the nuts on the back of the sheets making sure they are hammered all the way in and that they sit square.

If you need to mount bolt hangers for lead climbing, then you must reinforce the mounting for the bolt hanger. One solution is to use a 10cm x 10cm x 2mm thick steel plate with a 12mm hole cut in the center and a M10 nut welded onto the back of the plate as shown above. The plate is screwed in place with 4 screws, one in each corner. Next, the sheets can be mounted onto the frame as shown below. Make sure that the frames are in line and parallel. This is made easier by laying another piece of 61cm wide plywood sheet undereneath the frames (as a working table). You should also mount extra timber supports across the back of the frames to keep the distance at the back (which will be against the wall) equal to the front, see below. Use 5 x 50mm countersunk screws as shown.

As each section is completed, ensure that your plan for the next section will vary from the previous one. As subsequent sections are completed, lay or stand them next to each other to get a feel for the finished construction. This helps you to see how to procede with the rest of the wall. You can see some sections below (the side panels have not been added yet). Below left, a single 61 x 300 cm section and right, 3 sections. At the bottom of each section there is a timber edge that protects the plywood and provides a flat edge that will stand on the floor when installing the sections.

The next job is filling in the sides. This is a good opportunity to use any off-cuts of plywood as shown below. It is only necessary to fill in where there are holes through the construction, you don't have to mount thin side pieces where only the frame is visible (this can be seen in the fourth picture below). Use a jigsaw to cut the pieces and plane the edges smooth afterwards.

When all the sections are complete, including the side panels, they should be sanded and painted with a good quality primer to ensure that the paint adheres well to the plywood. Use a short-haired roller for the job. For the 20m2 here I used just over 1 litre of paint. When this is dry you can apply the top coat which is paint used for concrete floors with a special sand mixed in.

After the primer, the top coat should be applied. For this I use paint designed for painting concrete floors - which you can get in a range of standard shades of grey. To achieve a rough surface with excellent friction you should use very fine sand. The sand is actually designed for the purpose of adding friction to the surface when you paint a floor and can be obtained from a good paint shop. Firstly, paint a section of wall and then using a yoghurt pot with holes in the bottom, dust the painted surface with the sand as shown below.

After dusting the area with sand, use the roller to press the sand into the paint. The result is the surface shown below left. When all the sections are painted, final details such as bolt hangers can be added before the wall is mounted in its final position.

Any bolt hangers can now be mounted where the reinforcing plates are mounted on the back. Do not mount the hangers with bolts with countersunk heads, use bolts such as those below. Below right, the corner of the hall where the new boulder wall is to be mounted.

The wall sections are bolted to the wall as shown below, using 10mm threaded rods cut in 15cm lengths. In solid concrete the rods are glued in place in a 12mm hole. In brickwork with bricks that have holes in, you need to use a plastic insert to contain the glue. The glue is an expanding 2-component type that actually sets like concrete. When the glue is solid, the sections can be bolted in place. Use locking nuts and large washers.

When mounting the sections you will most likely have to remove some of the side panels to get to the bolts in order to tighten them. The picture below shows the finished bouldering wall and Bjarne christening the wall. He was so eager to try the wall out that we didn't even have a chance to get the crash mat in place or all the holds screwed on.

Hjerm Climbing Club Page          Main Page          Hovedsiden