UKC

I'm planning a 30° wall in my garage. It'll be about 2.5m x 2.5m. I'm trying to decide what type of panel to use. Ordinary ply seems to be about 35 > 40€/m². OSB/sterling board on the other hand is less than 10€/m². Would OSB be strong enough or would the T nuts tend to pull through? Would I have to increase the thickness - say from 18 > 22mm - to get the same strength as ply? Would I be wasting my money and be better off biting the bullet and buying ply in the first place? Thanks.

In reply to jon:

18mm OSB is fine for a private wall, I can't see you ever pulling an M10 Tee nut through a sheet of that. If you are worried about stability then just use a shorter distance between studs.
I have a 40 deg moon board made of 18mm OSB with studs stupidly at about 750mm centres (silly miscalculation that somehow slipped through the net until I'd built the flipping thing) and it's never moved at all. If you had 600mm centre studs you'd be absolutely fine.

In reply to Dandan:

Thanks.

In reply to jon:

One thing to think of, if you're going to be using screw on holds at any time in the future, then ply would be a better bet in my experience.

In reply to mrchewy:
I just trawled through a hugely exciting document that tested pull-out strength on various ply and OSB panels, their conclusion was that you get more variance due to the natural properties of the wood than you do from any specific type of ply/OSB, they all scored broadly similar results.
I'd have been inclined to agree with you but thought I should check.

In reply to mrchewy:
Ah, good point, thanks. I've already got all the holds from a wall in our old house. All but a handful fix to 10mm T nuts. The only screw on ones are little footholds. I suppose I could always make the kicker board from ply.
Edit. Though from what Dandan sjust posted it shouldn't be too much of a problem.

In reply to Dandan:

Interesting Dan. Real world experience of disabled toilets has lead me think that sterling board is pretty crap at holding a screw compared to ply. Old folks pulling on rails tends to need lots of remedial work and more often than not, it's a sterling board pad that causes the issue.

Happy to be corrected on that but I'd be interested to know in the testing system and if that's a direct pull out or a real world one ie disabled rails.

In reply to mrchewy:

That was for direct pulls, perhaps when there are shear forces involved then the OSB doesn't fare so well, which would be more relevant to climbing holds. Maybe a ply kicker is the way to go...

In reply to ericinbristol:

Cheers Eric! Labour of love!

In reply to jon:

I'm currently in the process of building a board myself. I struggled with the same questions. You can get different grades of OSB, each having various properties but I thought you'd want OSB / 2 at least and ideally OSB / 4? I've used OSB to build an extensive timber out building (15m^2 and 2.5m tall) and it has thus far been generally great. The only issue Ive found is if it get's any significant amount of water in it, then it's rubbish and this stuff is OSB / 4 22m thick! I've also found OSB flexes considerably under load if not supported sufficiently (I used off-cuts to make shelves).

I went for 18mm QMark Plywood from buildbase, which is costly but it should be completely solid. The biggest concern I have with this stuff is it weighs a fair old bit so I might need to beef up the support structure. Either way it'll be solid!

What size timbers are you using for the framing and what separation are you using?

In reply to jon:

I've built ours from P5 marine-grade chipboard (dalle aggloméré hydrofuge). Cheap as chips and bulletproof, No sign whatsoever of any inherent weakness in the wood that will ever be significant in the next century!

One thing I have learned though (something that most likely is common to any board type) is that you need a sharp bit when drilling the nut holes, otherwise the surface breaks up a little around the hole as the bit emerges, then the t-nut will be less stable.

In reply to jon:

If the wall is anywhere that your good lady will see it, use ply. If you use Stirling board, you will be continually under pressure to get rid of that ugly thing.

In reply to 3leggeddog:

It's the good lady who will be using it most of the time, though I agree, it's not that great looking.

In reply to crag_hopper_Jay:

I think I'm going off OSB and thinking about John's idea...

In reply to jon:


To give you an idea how good this stuff is, I built a cellar wall in our old house in Sheffield. Lasted 10 years. During that time the drain cracked and water leaked into the cellar. Water was 2 feet deep for about 2 months before we got it fixed. Once it was pumped out and left to dry the boards were still solid as ever and we didn't lose the use of a single t-nut.

In reply to john arran:

OK, just been looking at that. Did you use the tongue and grooved boards or regular straight edged? What thickness - 19mm? What spacing were your studs? I take your point about the drill bit - when I've drilled this stuff I've generally clamped a timber stud behind the board so the bit doesn't just break out a chunk of board.

In reply to jon:

I've used various thicknesses according to what I could easily get hold of when i wanted to build the next phase of the wall, and just varied the spacing to suit the rigidity and angle. Mostly the panels were odd shapes anyway as I have a lot of changes of angle and a lot of diagonals, so fixed spacing wasn't ever really an option. It isn't an exact science and I've never been that conservative but even the 19mm is pretty rigid so it's hard to go too far wrong.

In reply to jon:

Oh yes, and definitely tongue and groove. Gives a perfectly smooth and mutually supporting join with minimal effort.

In reply to john arran:

Thanks, John.