UKC

I'm hopefully moving house soon and am trying to redesign my lock-down circuit board (currently in bits getting in the way in the garage), for the new place.

The original board was free-standing and has a 3mx0.6m kicker with an adjustable angle 3mx2m hinged board mounted on the top and was adjusted by a 3:1 static rope pulley systems between the base of the kicker and the base of either leg with chunky locking pins. It adjusted from vert (pointless!) to around 30 degrees overhanging but the new one would probably need a minimum overhang of 18 degrees to accommodate a lower ceiling with a max of at least 45 degrees.

I'd love to be able to do away with the chunky 4x4 legs and mount it off an internal brick wall instead if possible and either adjust it with a pulley system or even possibly with a cable winch. I'm not sure how feasible this is however so am seeking some advice.

By my (very) rough calcs, the total weight of the top board would be around 250Kg if fully laden with holds (mostly wood but some resin bolt-ons, I used a generous 0.5Kg average hold weight for the calc), including the frame, ply sheets, t nuts and bolts. 330 ish Kg with me on it as well. Sound about right? Obviously we a dealing with levers here though so forces concerned depend on the angle and height of the load with a certain amount being shared with the kicker and the floor.

Do you think an internal brick wall could handle the kinds of lateral loads required for this kind of wall? I seem to remember something similar in Ingleton Wall but that was years back I saw it.

If so, what kinds of fixings would you use and how would you spread that load?

Or am I just being daft even considering it?

Thanks in advance, advice much appreciated!

How thick is the internal brick wall you'd be connecting back to?

That's a good question! I'm not moved in yet so can't say for sure. It's the party wall of a fairly solid looking 30s semi detached house though if that gives any clues. 

I realise this creates a 'how long is a piece of string' situation

There are brick walls and there are brick walls so without making an assessment of the state of your brick wall it's quite hard to say!

Honestly, I've dealt with a lot of brick walls where the act of drilling a hole in the wall liberates not only the brick in question but several around it.

However, my advice would be pretty much the same regardless:

Construct a wall plate and extend this to the ceiling to spread the load and attach your load to that.  This could be as simple as a 2x4 timber located at the top of the wall and screwed to the wall (frame fixings) and ceiling joists (long timber fixings).

You could also hang your board from the ceiling - assuming this has a load bearing floor above it's the same as putting it on the floor in the room above. Again spread the load with a plate (2x4s).

It depends on which way your ceiling joists run. If this isn't favourable you could run joists along the ceiling (with hangers into the wall) in the other direction and fix them to the ceiling above.

I think 250Kg is a little optimistic for the weight of the wall. 5 panels @30Kg + same for supporting structure + same for holds + same for one strong climber dynoing ~ 600Kg

Thanks for that. I hadn't considered mounting the the ceiling but it seems to make good sense to spread the load onto something that we know can take the weight.

Here's what I based it on:

The outer edge of the frame is 2x4 with 5 vertical 2x3 studs and 2 rows of noggins which I estimated at around 42Kg total with fittings. - edit: This does seem suspiciously light...

6 square metres of 18mm ply  - around 55Kg

Then 150ish Kg for 260 odd holds and fixtures (an overestimate as many will be small feet and wood, maybe offset by a few Ply volumes)

As for the dynos, that's sadly not really a thing on a 2.6m high wall as the ceiling spoils all the fun very quickly. But yeah cheers, It's defo worth considering the extra force moving on it will create.