# Help!



## Rayndeigh (Apr 14, 2020)

My husband and I are building a climbing wall and we seem to have vastly overestimated our ability to cut wood at an angle so that it will lay flush. Is there any way to fix this? Could we use a construction adhesive /gap filler and then an additional piece of wood to patch this by screwing it on over the spaces?

Thank you so much


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## TimLanier (Feb 15, 2019)

It's hard to tell just by looking at the closeups but I'd be concerned with the overall structural integrity of that wall. Looks a little shaky to me. I don't think I'd trust those little metal plates if that's all that's going to be holding the boards together while you're hanging off of them. Maybe you've already done this but I think you should show your project plans to someone with some design expertise to see if this is structurally sound design.


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## MadMark (Jun 3, 2014)

Thru bolts are called for, not screws or splicing plates.

You might want to use something better than #2 common. Knots have little flex strength.

A bevel gauge and more care when cutting will help. A better design will help more.

Lap joints will add wracking resistence.

Make sure your homeowners policy is up to date before letting others use this.


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## LesB (Dec 21, 2008)

Those plates pictures are not intended for this purpose. Also construction adhesive will not work here.
Are you covering the face with something? 3/4" plywood per chance. That would reinforce everything if properly secured to the framing. That would probably be your best option.

You could over lap over the joints with 3/4 " plywood plates on both sides through bolted to the 2X4s or get some metal strong ties (1/8" steel plates) and add them on both sides and bolt together.

Lap joints would have been a better approach but for what your are constructing they might still need bracing unless you face it with the plywood mentioned above.

Good luck.


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## JohnMcClure (Aug 24, 2016)

This could be interesting. A general idea of what you are doing would help.


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## CaptainKlutz (Apr 23, 2014)

+1 All of the above.

What angles did the plans call for?

Watching.


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## homestd (Sep 10, 2018)

Plans and pictures please…


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## Rayndeigh (Apr 14, 2020)

Here's what we actually have so far 

















We were going for a modified version of this at a 21 degree angle and with the different supports you see in my version. The climbing surface, which is good quality 3/4 in plywood, will be 8×10. 









Would using spare plywood over the joints work to secure it? We are also thinking of changing the design to something more simple, even though it means losing the work we've done.


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## craftsman on the lake (Dec 27, 2008)

The plywood plates mentioned above would be what I'd do.

Lots of ways to do it. But, to keep what you've got. Remove the metal cleats and replace them with triangles of 1/2" or 3/4" plywood.

Just put a square of plywood, maybe a foot square at along the side of the top corner and trace it. then cut it out, lay in along the outside (or inside) of the wood and use a few deck screws to secure it. Do the same with the other joints.


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## Rayndeigh (Apr 14, 2020)

To make sure I'm understanding what you're suggesting - you're basically saying that we can use plywood cut as you suggest in place of the plates that are currently attached and that that will be strong enough to connect the two 2×6s, despite the space between them?

And that would be strong enough to support my husband and I climbing on it? He weighs more than me (170ish lbs), but I'm the climber of the house, so I'd (140ish lbs) be jumping around on it more. We can definitely do the same thing on the other side as well, if it'll hold.


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## JohnMcClure (Aug 24, 2016)

Yes, use spare plywood to cover the joints in your triangles. It'll hold. 
I'm more worried about the triangles "toeing out" once theres weight on the system. Need to be smart about attaching them to the climbing wall. But you'll get there - keep doing what you are doing, have fun, learn.
Looks fun.


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## craftsman on the lake (Dec 27, 2008)

> To make sure I m understanding what you re suggesting - you re basically saying that we can use plywood cut as you suggest in place of the plates that are currently attached and that that will be strong enough to connect the two 2×6s, despite the space between them?
> 
> And that would be strong enough to support my husband and I climbing on it? He weighs more than me (170ish lbs), but I m the climber of the house, so I d (140ish lbs) be jumping around on it more. We can definitely do the same thing on the other side as well, if it ll hold.
> 
> ...


Before roof trusses were mad in a factory we used to make them with the corners braced with plywood. Plywood is made of laminated sheets glued together with the grain of each layer going at right angles to the previous layer. It has very high shear strength. Make sure the triangles are large enough to brace the corners.


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## Sylvain (Jul 23, 2011)

Make big triangles as shown by 'Craftsman on the lake'.
Glue them with PVA glue and screw them before the glue sets. The screws will act as clamps

Put also one where the bracing meets the upright.
Choose plywood with at least 5 ply.

interesting resource:
https://serges-peladeau.wixsite.com/tecniques-sceniques

look for "mouchoirs" in "diaporamas" (it is in French language)


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## Sylvain (Jul 23, 2011)

Perfect meeting of the pieces doesn't seem to be necessary.
However, you might want to try this technique:
Pass a hand saw between the two surfaces as shown in this boat building technique:
http://blog.douglasbrooksboatbuilding.com/2019/04/2019-bates-college-short-term.html

look at second and third picture where the students saw between the two horizontal boards


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## Lazyman (Aug 8, 2014)

With a quick scan through the replies I did not see where anyone addressed your original question about making accurate angled cuts. You didn't say what tool you are using to make your cuts? Are you cutting by hand, circular saw, miter saw, table saw, something else? If your measurements are correct, you should be able to get a flush joint, which will help make the joints (with the plates recommended above) stronger. A miter saw would probably be the easiest to use, especially if your angles are odd ones that are not easy to layout without a very good protractor or a good understanding of how to use a framing square to do it.

Also, IMO a better and probably simpler approach would be to make the wall by framing the rectangle with your 2×4s (or are those 2×6s?), attaching the plywood skin (lots of screws with a bead of construction adhesive on each stud) and then attaching the wall to the angled support legs. Note: before attaching the plywood face, make sure that it is square by measuring the diagonals

BTW, assuming that wall is 8' wide and 10' tall, you can save yourself some cutting by turning the plywood sheets sideways instead of vertically. Only one cut required to cut the 2' piece to put at the top or bottom


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## Rayndeigh (Apr 14, 2020)

That is exactly our plan for the plywood, which is why I have extra plywood to use for the triangles - the second half of the 3rd piece is just lying on my floor right now. The rest of it is t-nutted and ready to go. We used a circular saw to cut the wood. My husband is a math guy, so I'm confident that our measurements are correct. He also seems to understand how to use the protractor and square, but it's possible that the protractor isn't very good (it was definitely one of the cheaper ones at the store). My guess is still that we just aren't that great at applying all of our conceptual know-how. The question at this point is really whether the fixes suggested here will salvage what we've already got safely, or if we should scrap it entirely.


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## Lazyman (Aug 8, 2014)

Your drawing shows that each of the vertical studs are angled at both ends. My recommendation is to make them square, which will save you from having to make all of those angled cuts and simplify the construction of the wall panel. It also allows you to slightly adjust the angle the wall is tilted without changing the wall design, should that be necessary as you fix the joints on the supports.

If you don't want to buy a miter saw, my recommendation is to clamp or even temporarily screw a guide at the correct angle to the board to guide the cut. My circular saw's foot plate is 4" (which is fairly common I think) from the edge to the saw blade so clamp the guide at the proper angle, 4" away. By sliding along the guide, it is much easier to get an accurate cut. Also remind him to layout a right triangle and measure the other angle to check that it is complimentary as a way to check the angles to verify that the protractor or whatever method he is using to layout the angle is accurate enough.

EDIT: Corrected supplementary to complimentary angles.


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## LeeRoyMan (Feb 23, 2019)

> The question at this point is really whether the fixes suggested here will salvage what we ve already got safely, or if we should scrap it entirely.
> 
> - Rayndeigh


If you add the plywood pieces (as shown above) it will be fine. No need to scrap it.
Use glue and screws when you add the plywood.


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## Rayndeigh (Apr 14, 2020)

Oh, another question - what's the best way to remove the plates that are on right now (since, as I understand it, they have to come off before attaching the plywood)? Just the back end of a hammer (and removing the screws, of course), or is there some other trick?

Thanks so much for all of the advice. This has been incredibly helpful.


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## Rayndeigh (Apr 14, 2020)

One last question (hopefully)

Should the plywood plates be the same hardwood plywood as the wall, or can they be slightly lower?

Thanks so much


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## craftsman on the lake (Dec 27, 2008)

> One last question (hopefully)
> 
> Should the plywood plates be the same hardwood plywood as the wall, or can they be slightly lower?
> 
> ...


If it's 3/4" plywood any kind will do as long as it's plywood which is laminated sheets.


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## Unknowncraftsman (Jun 23, 2013)

I used to build roof trusses if we ever had to remove nail plates we used one of these. Our plates were very large and were pushed in with a hydraulic press. Your should come out very easy with vise grips and small prybar.


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## LeeRoyMan (Feb 23, 2019)

> One last question (hopefully)
> 
> Should the plywood plates be the same hardwood plywood as the wall, or can they be slightly lower?
> 
> ...


They can be thinner, 1/2" thick at least though. 
You could also leave the metal plates on and put the plywood on the opposite side?


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## MadMark (Jun 3, 2014)

Tie both sides together at the base to prevent splaying.


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## Sylvain (Jul 23, 2011)

- What will you do to secure the climbing plates and prevent them from sagging?

- how to saw accurately by hand
look at this video:





marking the cut at about 5' 30" 
guiding the cut and sawing at about 12' 20"

or look again at about 21' 35" 
The guide is made by the combined action of the knife line (aka "knifewall) and the chisel making a little trench for the saw.

No need to invest in machinery where a hand saw will do.


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## Sylvain (Jul 23, 2011)

Class I, class II and class III hand sawing 
in this video:


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## Rayndeigh (Apr 14, 2020)

Will it be safe if we just put the plywood triangles on the outside and use stronger plates or something on the inside? They'll interfere with the climbing wall (although we might have come up with a work around).


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## Rayndeigh (Apr 14, 2020)

Okay actually a better question because we put the plywood triangles on both sides already in one place - if we drill a pilot hole, will it be safe to drill into the edge of the plywood of the climbing wall? Otherwise one of the pieces won't be attached all the way down on the sides (although it will be attached to the middle joists).

Thanks so much


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## MadMark (Jun 3, 2014)

Um, how big are the holes for the handholds? I'd back them with a metal plate to prevent pull thru. How big are the people you expect to use it? Is it just for you and hubby or are you expecting other users?

You have to have enough backing material to support the hold as a single point dynamic load. Has anyone done the load analysis or are you just winging it?

The plywood mounting needs work. Things *will* flex. I'd hate to see a piece of ply rip off because of screw pull thru.

Who pays if it fails & someone gets hurt?


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## Rayndeigh (Apr 14, 2020)

The holes for the holds are 7/16 and tnutted and are 8 inches apart. Here, you can see the front and back of the panels. This is industry standard. Considering the world situation right now, I'm pretty sure it's just my husband and I climbing on it for some time. I'm trying to make it safe, though, which is why I'm asking so many questions. We definitely chose a design that was way more sophisticated than we were equipped for, but we didn't realize until we were already building.


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## MadMark (Jun 3, 2014)

The tee-nuts give me pause. How thick is the plywood and what grade is it?

Read this

Tee-nuts are *not* designed for dynamic loads. The numbers shown were for *static failure.* Catching your entire weight on *one* may well exceed the tee-nuts load rating. Repeated stresses may cause pull thru.

I can't help but think commercial climbing walls are built by welders, not carpenters.

How are you going to bolt this to the floor?

As a retired engineer a little warning bell goes off as I review your plans. They look sorta-kinda ok, but I'd really like to see the stress analysis vs the materials and a detailed dimensioned drawing. Everything should have a safety factor of 2X or 3X.

It my well be ok, but I don't like how it smells.


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## Rayndeigh (Apr 14, 2020)

The plywood is 3/4 inch hardwood, which is also industry standard.


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## MadMark (Jun 3, 2014)

Ok, I'll shut up. It's just …


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## Rayndeigh (Apr 14, 2020)

Sorry, I hadn't seen your whole response when I wrote that. My bad.

Many commercial gyms have wooden walls similar to this in addition to their bigger walls. Those walls are often built by their routesetters, not welders or carpenters. I can't speak to your issues with tnuts, except for to say that they are industry standard and I've been climbing on them for years. If the Olympics were going forward this year and you watched the climbing, you'd be watching climbers doing all kinds of crazy moves on holds that are primarily attached with tnuts (and generally screwed on in order to stop them from spinning). I'm pretty solid on the wall info, which is why I'm seeking information on the frame.


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## CaptainKlutz (Apr 23, 2014)

Madmark2 - IMHO your are not crazy. If you are, then so am I !!!

I KNOW those fastener's are a marginal design unless it's used by people less than ~125-150lbs. 
Found out hard way. 
Son's friend built one of those walls using same T-Nut anchor methods. Couple of 225-250lb bruisers ripped out some lower foot steps goofing around (doing back flips off the wall?). He asked me to help him fix the damage. Was able to mount a steel plate behind the damaged plywood, with welded nuts on back to replace the t-nuts.

Was told commercial walls use heavier fiberglass laminated plywood or all FRP back walls, and metal plates/strips in back to distribute load of wall accessories for 'military grade' climb training? 
Only know this trivia as several climbing gyms won't let my 6'6" 250lb 'kid' climb due weight restrictions. LOL

Wish OP best of luck with project. 
Looks like fun!


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## MadMark (Jun 3, 2014)

Been researching. Four prong, not three, tee-nuts are used. Some even have built in 2×2 backing plates. *None* are from your local BORG.There is lots of talk about tee-nuts becoming "spinners" and needing replacing/relocating. There is also mention of "pull outs" which is my concern.

Frames are *usually* steel and only occasionally wooden (like rollercoasters). The plywood used is T&G (Tongue & Groove) so the panel edges don't move under stress.

The climbing surface can't really be freestanding without a lot of engineering.


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## Rayndeigh (Apr 14, 2020)

I used 4 prong tnuts that I purchased from a reputable climbing company. You're right that most walls aren't plywood anymore, but they used to be. There are many schlubs like me building freestanding walls right now and many who have done so in the past. I've climbed on a good number of them. What I would like to know right now specifically is whether I can screw into the edge of the plywood if I use a pilot hole or not (as I've seen on the internet in my own research), or if the plywood would still be likely to splinter.


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## Lazyman (Aug 8, 2014)

> Okay actually a better question because we put the plywood triangles on both sides already in one place - if we drill a pilot hole, will it be safe to drill into the edge of the plywood of the climbing wall? Otherwise one of the pieces won t be attached all the way down on the sides (although it will be attached to the middle joists).
> 
> Thanks so much
> 
> - Rayndeigh


If you are asking about driving the screw into the edge grain of the plywood, that is usually not a good idea. It can cause the laminations to separate and the screw may just pull out.

If that is not your question, we need a little more info or pictures.


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