Building climbing volumes

From Climbing Training Wiki

Volume Builds[edit]

550x150 Pentagon Volume
550 x 150 Pentagon Volume.png

30 deg Square Volume
30deg square volume render.png

Large Flat Triangle
Large Flat Triangle Volume .png

Small Triangle Volume
Small Triangle Volume Render.png

Small Triangle With Flat Edge Volume
Small Triangle With Flat Edge.png

Required Tools[edit]

  1. Pencil or Pen
  2. Countersink Bit
  3. 2.5mm Drill Bit
  4. Magnetic Angle Meter Level Protractor or Angle Finder ruler
  5. 150mm Mechanics Vice
  6. Timber top Workbench
  7. 600mm 24in Stainless Steel Rule or other ruler
  8. 185mm 1200W Corded Circular Saw
  9. 100mm 720W Angle Grinder (with Flap Disk or Saburrtooth 100mm Medium (or Fine) Flat carving disc (prefered)) OR sander (any type)
  10. 12mm Spade Drill Bit
  11. Handheld Drill (Cordless is better)
  12. Small paint roller or paintbrush
  13. Jigsaw
  14. Angle Finder Ruler or Protractor
  15. Painting Drop Sheet
  16. Paint Scraper


  1. Safety Glasses
  2. Work Gloves
  3. Ear protection
  4. Mask or Respirator


  1. 2400 x 1200 x 17mm F8 Structural CD Plywood
  2. Paver Sand
  3. Clear Polyurethane Timber Varnish
  4. PVA Wood Glue
  5. M4 Zinc Plated Countersunk Washer
  6. Wood Putty
  7. Low Sheen Exterior Paint
  8. 8 - 10 x 40mm Treated Pine Countersunk Head Screws
  9. 8 - 10 x 50mm Treated Pine Countersunk Head Screws
  10. 8 - 10 x 60mm Treated Pine Countersunk Head Screws
  11. M12 Stainless Steel Round Flat Washer (if making bolt on volumes)


  • Power tools are dangerous. If you are not careful you will cut off your fingers, hand, and other injuries.
  • Keep a clean, tidy work area.
  • Make sure you have bought the required tools, PPE and materials.
  • Go slow, measure twice cut once
  • Print out the pdf design for the volume you want to build and this page for the instructions
  • Texture your volume with fine sand. Make sure it is VERY DRY sand before you apply it


Sketch out design[edit]

Volume Build 01 Measuring.jpg

  1. Draw out the volume pieces onto the plywood. Optionally use a protractor to make sure the internal angles are correct.
  2. Mark each edge (on the inside so its not cut off) with the length of that edge (for identification) and angle that it needs to be cut at. Make sure you leave space between each piece.
  3. Mark down the side that is to face the outside as 'outside' so its clear where the angled cuts go.

Cut out volume pieces[edit]

Horizontal Cuts[edit]

Use your PPE and don't cut your fingers off!

Horizontal cuts are when your plywood is lying flat on the table. They are marked as 'Horizontal' on the design sheet. Vertical cuts still need an initial 0 degree (straight up and down) cut before they are placed in the vice for a vertical cut. You may find it easier (and safer) to do horizontal cuts by screwing the plywood to your workbench so it doesn't move around. You can also use a clamp.

  1. Use your jigsaw to roughly cut out the pieces from the plywood. (If you don't have a jigsaw you could try cutting them out directly using the circular saw). Leave some space - don't cut straight on the edges, that is what the circular saw is for. Keep your hands and cables out of the way.
  2. Use your circular saw to cut the exact shapes. Make sure you cut to the outside of your drawn lines. Any edges marked as 'Horizontal' can have their angles cut directly on the workbench. Any edges marked as 'Vertical' will need an inital 0 degree cut to the edge, then proceed to the steps below ("Vertical Cuts" - angles are greater than 45 degrees and cannot be cut horizontally by a circular saw) Go slowly and take care not to stray inside the lines. (The reason you use a circular saw instead of a jigsaw is because the circular saw will cut straight lines instead of wobbly ones)

Volume Build 02 Cut Angles.jpg

Vertical cuts[edit]

Volume Build 03 Vertical Cuts.jpg
After your shapes are cut out, do the vertical cuts. Vertical cuts are needed when the required angle is less than 45 degrees. So you'll have to put the plywood piece in a vice vertically and cut it that way instead.

  1. Grab a piece of scrap plywood about the same length and screw it to the shape you are cutting. It's used to create a larger flat surface to balance your circular saw.
  2. Make sure the 'outside' face of the piece is screwed or clamped facing the scrap plywood. You want to cut into the inside face of your volume piece.
  3. Place both together into a vice with the edge you want to cut facing up.
  4. Set your circular saw cutting angle to the angle written on the design sheet. Use a protractor or stick your magnetic angle protractor on the saw blade to check the angle is correct, as most saws only have marks for 15, 30 and 45 degrees.
  5. Do the cuts for each vertical cut. Make sure the blade is cutting into the inside face. Keep fingers, power cord out of the way. Try to keep your circular saw straight and level to cut the correct angle.

Volume Build 04 Vertical Cuts 2.jpg

Drill the T-Nut holes[edit]

  1. You can put the holes anywhere you like, except not too close to each other and not too close to edges (5-6cm). Grab your 12mm spade drill bit and drill out all the t-nut holes on each piece of the volume. Drill from outside face to inside as the inside ply will splinter out when the bit comes through.

Volume Build 05 TNut holes.jpg

Assemble Volume[edit]

Volume Build 06 Screw and Glue.jpg

  1. Grab some scrap timber or ply which have straight edges. Screw them or clamp them down to your workbench to act as a frame for constructing your volume. For example if your volume is 200mm wide, screw down two pieces of straight timber 200mm apart on your workbench. You might not have to do this, sometimes just use a few bricks to hold it all together while screwing.
  2. Assemble the pieces of the volume inside the frame on your workbench.
  3. If they don't fit well, this means that either your measuring or cuts wer wrong (too long or short edges) or your angles are wrong. So check your edge lengths, if you made a mistake, fix it up or cut a new piece. If your angles are wrong, you can use your angle grinder and flap disk/grinder wheel to increase the angle slightly. Increase the angle a bit then try again. Repeat until the volume pieces fit perfectly.
  4. Put wood glue along each edge (except the bottom edges)
  5. Join each edge with the adjacent piece. Drill pilot holes with a 2.5mm drill bit first. (Make sure you get your angles right - otherwise the screw will stick through the surface of the volume, or it will not bite hard onto the other side and stick through on the inside. If this happens, reverse the screw out and drill a new hole.) You may want to drill one pilot hole per edge first, and screw them just to hold everything together.
  6. The number of screws you use per edge depends on the length. You'll need at least two. For lengths greater than 300mm, add three or more. They should be alternating (one from one side, then next from other side).
  7. After you finish pilot holes, use the countersunk bit to countersink each hole. This stops the timber splitting when you drill the screws in
  8. Place screws in. Use 60mm or 50mm screws. Screw firmly but not hard enough to split the plywood surface or thread the hole.

Volume Build 07 Screw Configuration.jpg

Drill holes for fixing the volume to climbing walls[edit]

Fixing volumes to climbing wall.jpg

  1. Drill pilot holes for the screws that will fix the volume to the climbing wall. These holes should be spaced apart evenly across the length of the edge. Two holes for < 300mm and three holes for > 300mm. You need to start each pilot hole 40mm from the edge to leave enough plywood for it to be strong enough not to pull through (see photo above). Vertical faces also should have their pilot holes angled in towards the volume by 15-30 degrees or so (but no more!); whereas angled faces can have holes drilled straight down.
  2. After you drill the pilot holes, use the 12mm spade bit to recess the hole. It should be recessed enough for the M4 countersunk washers to sit inside the hole flush (not poking out of the volume)
  3. Add a dab of glue and place the M4 countersunk washers inside each hole - with the countersunk side facing outwards

Pre-painting work[edit]

Volume Build 09 Sanding.jpg

  1. Take either a sander, angle grinder with flap disk or saburr wheel and smooth off the joined edges. It's up to you how much, but you want it to be hand friendly, not sharp.
  2. Fill up any holes (except for the holes with the washers) with putty
  3. Sand down any excess putty until it is flush with the plywood


Volume Build 10 Paint and Sand Coating.jpg
Volume Build 11 Final Texture.jpg

  1. Paint your first layer on the volume
  2. Sprinkle dry (this is very important) and fine pure sand over the still wet, painted volume. The sand should stick to the paint.
  3. Leave it dry for 4hrs+ (depending on your weather)
  4. Gently bush off any excess sand.
  5. Give the volume another coat of paint and leave to dry again
  6. Give the volume a coat of clear polyurethane. This prevents the sand from flaking off when attaching holds or grabbing/stepping on the volume.
  7. Let it dry for 24hrs

Final Steps[edit]

  1. Attach t-nuts. If they are bang in t-nuts (with prongs), instead of hammering them in, grab a bolt and a climbing hold, and thread it on, then tighten it down into the plywood slowly. This makes it easier to put t-nuts on in tight places (such as in a volume) and makes sure the t-nut is correctly aligned.
  2. Use the correct size screws for attaching the volume to the wall. This is super important. You don't want a volume coming down on top of you. You may need anywhere from 40mm to 60mm or larger, depending on how much the screw comes out the other side. It should at minimum come out 20mm so the screw will go all the way through the climbing wall plywood panel.

Volume completed.jpg