In reply to Am Fear Liath Mor:
Er, yeah....mainly by trial and error! It is built from four main sections, plus the roof and inside corners. These four are the two walls and the back, which was built from two pieces and bolted together. It is VERY heavy (two people can just about carry one of these four main sections). It needs to be heavy to avoid vibration & rocking when you are climbing on it - and to prevent any danger of it toppling over (it won't, despite a couple mates having tried it for what could have been a quite painful and messy laugh)
We constructed wooden 'ladders' from timbers of 3" x 2 " or 4" x 2" cross section, depending on the position of the beams (corners are bigger as they have to be used to bolt the sections together). Each 'ladder' was about 7' 11" in length and was actually two ladder shapes side by side, with 4 'rungs'.
To the ladders we added the plywood, in 3' x 2' sheets, pre-drilled with a 12mm wood bit in a distribution suited to adding the T nuts, and pre-painted. Three sheets to a section, as the bottom of the wall has to be clear of the ground (to stop rot) and the top has to leave space for the roof beam.
The back was then made by joining two of the sections. These were bolted together with four very M10 long bolts (8 inches I think, mixing my units). Two cross peices were coach-bolted across the back of the sections to distribute the load away from the centre of the wall when it was climbed on.
Next, the back was attached to the sides, one side at a time. Again, we used M10 bolts; the angle was chosen at this point; it could have been made steeper, but we designed it for traversing circuits as we only had one bouldering mat then and didn't want to keep falling off onto concrete. Now we had an open 'U' shaped wall. The roof supports were made by screwing lengths of 1" x 2" timber along the sides and back of the wall and balancing the rof panels (plywood) onto them. Then two long pieces of timber were bolted to the corner supports of the wall, lying across the top of the roof above these sheets. The sheets were coach-bolted and screwed onto these timbers. So we had a half-box.
The corners were just knocked up from a simple frame screwed to pre-drilled, painted and T-nutted plywood and mounted onto the original wall's plywood using coachbolts that penetrated through into the frame behind.
The whole thing was then painted. I forget how many times! The corrugated roof protector was hammered on and a B and Q tarpaulin tacked down the back to channel any run-off straight to the floor behind.
Tools we used:
Socket set (essential) and spanners
Jigsaw
Drill
Hand saw
Assorted screwdrivers & electric screwdrivers
Hammer
Sledgehammer (used to tap the T nuts in gently, with less noise than a normal hammer makes - we were working quite late at night in the garden)
I think that was about it. I enjoyed building it, but now never find time to climb on it.
