Climbing wall

cletus

Have a section of wall in the back garden I'm planning to turn into a climbing wall for the kids.

The plan is to batten the section of wall with 4x2, the screw 18mm ply to that. The ply would have the t-nuts to secure the climbing holds.

Original plan was to use marine ply, but that's working out at about €100 a sheet, whereas normal 18mm ply comes in at about €30. What's the best way to weather proof the ply if I go "non-marine"?

Stigura

There's a reason for that price difference

I have some off cuts of " Exterior " 18mm, stood out in my kitchen. On a quiet night, the Dogs and I like to go out there and watch the stuff blowing apart!

Expose that carp to the elements? It's like time lapse! :eek:

Saying that? I made a pine marten box out of some. Absolutely slathered it with yacht varnish. I'll have a look, tomorrow. See how that's faired.

GinSoaked

Probably more expensive than buying decent timber to start with but you could cover it in glass fibre resin? Adding some colour and matting you could even make it look like rock?

cletus

GinSoaked wrote: »

Probably more expensive than buying decent timber to start with but you could cover it in glass fibre resin? Adding some colour and matting you could even make it look like rock?

It's an area of 5 sq.m, I don't like even trying to calculate the cost for that:D

The yacht varnish was my initial thought, perhaps if I can let all the exposed edges soak in it.

Or maybe seal all the edges with silicone, and varnish the face and back?

salmocab

You could cover the cheap stuff with marine ply

cletus

salmocab wrote: »

You could cover the cheap stuff with marine ply

In that case, I'd just buy the marine ply. I'm trying to keep the cost down, hence the opening post

GinSoaked

One thing I'd think of if using less than ideal plywood for the face material is putting some timber blocks behind the plywood to take the climbing wall handholds.

So if the plywood does start to suffer there is still something solid that the hand holds are screwed/bolted to. I don't mean covering the whole of the back with more timber just large off cuts where the handholds are attached.

cletus

GinSoaked wrote: »

One thing I'd think of if using less than ideal plywood for the face material is putting some timber blocks behind the plywood to take the climbing wall handholds.

So if the plywood does start to suffer there is still something solid that the hand holds are screwed/bolted to. I don't mean covering the whole of the back with more timber just large off cuts where the handholds are attached.

Normally speaking, the holds are attached by t-nuts, and usually they are spaced on a grid at gaps of around 100mm. This allows for changing the positions/adding and subtracting holds to create different routes. It's unlikely the t-nuts would pull through the ply, more likely that just fall out the back

Lumen

Even marine ply needs to be protected, particularly on the edges. And it's bloody heavy.

I'd go with the WBP ply and yacht varnish plan.

GreeBo

cletus wrote: »

Normally speaking, the holds are attached by t-nuts, and usually they are spaced on a grid at gaps of around 100mm. This allows for changing the positions/adding and subtracting holds to create different routes. It's unlikely the t-nuts would pull through the ply, more likely that just fall out the back

I think his point was that they will pull through if your ply turns to paper due to getting wet and rotting...?

GinSoaked

I didn't really know how the holds where attached the local timber yard make tree houses with climbing walls and their holds are just bolted through the plywood.

cletus

GreeBo wrote: »

I think his point was that they will pull through if your ply turns to paper due to getting wet and rotting...?

Yep, which is why I wanted a way to treat the ply. I'd imagine I'd notice that level of deterioration.

Think I'll try the wbp ply and yacht varnish.

Thanks for all the replies

GinSoaked

There is a product I was looking for that I've seen used on boats and I'm guessing its one like this in the video

maybe expensive to do all the plywood but might significantly improve the life of it if you do all the edges and any holes you have to make.

You still need to finish with a varnish.

GreeBo

Will it be an open or a closed structure?

I think open would be easier as you get to see all sides of the wood. If you try to enclose it I would worry about whats going on where you cant see it...

Oh and I would urge trying to get some sort of overhang/shelter on it. Makes a huge difference to the amount of water that reaches the "wall"

cletus

It's going on a garden wall. It'll be the size (roughly) of two sheets of ply. Not going to be a huge structure, but the chances of having a cover over it are non existent

GreeBo

cletus wrote: »

It's going on a garden wall. It'll be the size (roughly) of two sheets of ply. Not going to be a huge structure, but the chances of having a cover over it are non existent

I really just mean a "roof" type structure to divert direct rain away, even if its just a couple of feet of corrugated "stuff"

Will it be directly on the wall? The further off the wall you can keep it the better it will dry rather than rot.

cletus

GreeBo wrote: »

I really just mean a "roof" type structure to divert direct rain away.

Will it be directly on the wall? The further off the wall you can keep it the better it will dry rather than rot.

4x2 on the wall as battens, screw the ply to this

GreeBo

cletus wrote: »

4x2 on the wall as battens, screw the ply to this

4x2 PT should be fine. How are you planning on fixing them to the wall?

What have you specced for the ply to batten?

Stigura

Okay, Cletus; I've just been out and grabbed a cursory look at my piney box. Couldn't physically get up with it, because my ladder's off site.

From what I can see? Ummmmmmm ..... Mmm. I'd say it'll weather another winter. Then, I'm thinking it'll definitely need coming down. A bloody good inspection. Almost certainly some touching up with more varnish. And I gave it Three coats, to start with!

So, that'll be about your own future, mate. Pour gallons of varnish over it. Then, be for ever out there, looking at it for signs of cracks. Then, certainly rinse and repeat, every year.

I was gonna say; " So; How does this stuff work on yachts?! ". But, of course; They don't make yachts out of crap ply!

Hold fire though. I Might have something in my work room ..... :cool:

cletus

GreeBo wrote: »

4x2 PT should be fine. How are you planning on fixing them to the wall?

What have you specced for the ply to batten?

Express nails.

I don't understand the second question. Are you asking what screws I'll use? Decking screws, or galvanised screws, or some other suitable outdoor screw

GreeBo

cletus wrote: »

Express nails.

I don't understand the second question. Are you asking what screws I'll use? Decking screws, or galvanised screws, or some other suitable outdoor screw

You just need to factor in that your screws will be subjected to different forces (shear) as they are in a wall rather than holding down a deck. Plus they need to survive outside in treated timber.
Same goes for your express nails.
PT timber can eat through the wrong type of fixing, especially if copper is used in the treatment process.