VOLUME

Best plywood for climbing volumes

Material choice decides whether a DIY climbing volume feels solid under dynos or flexes and sheds T-nuts. This guide covers plywood grade, thickness, sheet size, and hardware that match planar wooden volumes — the kind you design and cut from flat panels.

Recommended thickness

Use at least 18 mm (about ¾″) structural plywood for faces that take bolt-on holds. That depth seats standard climbing T-nuts and resists pull-through far better than 12 mm or ½″ sheet. VOLUME’s default wall thickness is 18 mm for this reason; you can set 0–40 in display units, but going thin for “weight saving” on a climbable face is rarely worth it.

Plywood grades that work

  • Baltic birch — dense, many thin plies, clean edges for CNC and hand work; preferred for commercial-feel volumes
  • ACX / exterior structural — common in home walls; “A” face out for the climbing surface
  • Avoid soft interior underlayment or boards full of voids where T-nuts can crush the core

VOLUME’s manufacturing interest path mentions Baltic birch specifically for shop-built volumes; DIY builders should aim for the same class of sheet when budget allows.

Sheet size and waste

European sheets are often around 2500×1250 mm; North American DIY frequently uses 4×8 ft. Design with your real blank in mind: nest panels with a small gap (VOLUME nesting defaults include an 8 mm gap) so you do not discover mid-job that the roof panel does not fit.

Glue, screws, and finish

  • PVA or polyurethane wood glue on panel joints plus mechanical screws
  • Pilot holes into plywood edges to prevent splitting
  • Sand edges; optional paint or texture after drilling strategy is clear
  • Do not rely on drywall screws — use proper wood/construction screws

Hardware

  • Climbing T-nuts matched to your hold bolts (commonly ⅜″-16 in many markets)
  • Drill bit sized for a snug T-nut barrel (often ~7/16″ / ~11–12 mm depending on nut — verify yours)
  • Longer mounting screws that reach wall framing through the volume shell

Layout details: T-nut spacing on climbing volumes.

Design thickness in the software

Set wall thickness in VOLUME to the plywood you will buy. Mitres and shell thickness in exports follow that value. If you change thickness after cutting, panels will not match the files.

FAQ

Is OSB OK for volumes?

OSB can be structural on walls, but plywood is the better face for clean mitres, T-nuts, and sanding. Prefer plywood for the volume itself.

18 mm or 21 mm?

18 mm is the usual DIY/gym plywood volume standard. Thicker sheet is heavier and harder to mitre by hand; use it when you have a structural reason.

Next: build the volume or design with the correct thickness from the start.