Help with cross brace on coffee table

[Keri Gollance]

Hello -

First off I'm a rookie! I'm building a walnut live edge coffee table. I've built 'X' style legs (lap joined). I want to build a cross brace from the center of each 'X' leg to the top of the underside of the table to prevent any lateral movement. If I make the cross braces so they meet in the middle of the table vs. braces with 2, 45 degree angles - the brace length difference would be 7 inches each - is that going to make a big structural impact. The total span between legs is 34". I have on hand 2 walnut pieces to make the shorter braces, but would need to go buy more to make the longer pieces. Is it worth it? I hope the question makes sense.

Thanks
Keri

[Brian Tymchak]

Hi Keri, I would think with the table doing light duty as a coffee table, that not having the braces meet will be just fine. In fact, I'm not really sure having them meet would add any stability to the piece, since the ends of the braces should be firmly secured to the bottom of the table top. If you like, and you have the material, you could add a cleat on the bottom of the table that runs between the 2 ends of the braces, if you feel that it will help. Or, another option if you feel strongly about having that brace braced against something, maybe you could cut a recess (mortise) in the bottom of the table top where the brace will land such that the brace is backed up by the table top itself. Maybe a mortise only 1/4" deep might necessary. That would depend on the thickness of your top. Actually, I think that would be overkill but I tend to over-engineer all my projects.. :rolleyes:

Make sure you post pictures when you are done!

[Pat Barry]

I think the two short braces you described, probably mounted at 45 deg angles to the top, would be fine, it may boil down to a question of appearance of the finished product. The question I have is what / how are you planning to attach the bracing to the crossbrace and to the top? Also, how are you attaching the cross-legs to the top? Screws?

[Clay Fails]

I am just finishing a coffee table where i have used cross braces on the ends, for decorative effect only. I'm not sure if this is what you are referring to. The table is joined with loose tenon Festool dominos. Cross braces are half lapped and tenoned in to the legs. I'll post more photos if this would help at all.

[Clay Fails]

A few more photos. The shelf and top are pretty much done, I just need to fit and finish them and put it all together. Black walnut.

[Edward Oleen]

Go with the 45* braces anchored to the top. They will definitely add to the table's stability: they will prevent rocking end-to-end. The legs themselves are "cross-bracing" the back-and-forth motion.

I'd attach them to the top with dowels through the brace and into the table top about 1/2 to 3/4 the thickness of the top. You must be careful in drilling the holes, of course...

The worst possible way of building a coffee table, or any table for that matter, is with four vertical legs - one at each corner and no skirting or other bracing. In this situation the whole anti-sway forces are concentrated at the leg-to-table joint, which is what? an inch square or so? When you add skirting the legs are attached to the skirting, and the top sits on top of the skirting.

[Keri Gollance]

Hi Pat -

I attached the legs to the top between two cleats which are attached to the table top. I did make a few of the screw holes in the cleats bigger to allow for the expansion across the grain. I attached the legs between and to the cleats. I also used cleats across the table to put the cross braces. I did attach the cross braces to these cleats but did not actually screw the cross brace to the table top. I ended up finding in my scrap pile longer pieces of walnut so I was able to make longer cross braces. It ended up pretty darn sturdy.

Thanks for replying.

Keri


I think the two short braces you described, probably mounted at 45 deg angles to the top, would be fine, it may boil down to a question of appearance of the finished product. The question I have is what / how are you planning to attach the bracing to the crossbrace and to the top? Also, how are you attaching the cross-legs to the top? Screws?

[Keri Gollance]

Hi Brian - I did end up using cleats across the length of the table to put the braces between. I actually screwed the braces to the cleats and not to the table. I like to mortise idea, but a little late at this point. One question, do you think it is necessary to also screw the brace to the table top? I still can but not sure if it is necessary?

thanks so much for your help.

Keri

[Keri Gollance]

That is a beauty. I will use this idea for my other walnut slab. I have been thinking of getting a Festool for dominos. I hear great things about it. Thanks for sharing - I love it.

[Brian Tymchak]

Hi Brian - I did end up using cleats across the length of the table to put the braces between. I actually screwed the braces to the cleats and not to the table. I like to mortise idea, but a little late at this point. One question, do you think it is necessary to also screw the brace to the table top? I still can but not sure if it is necessary?

thanks so much for your help.

Keri

Yes, I think you should anchor the cleat to the top. Without it each leg assembly still has only, at best, a 2 point connection to the top. Anchoring the cleat to the top will provide the 3rd connection point that will lock each leg assembly in place relative to the top, which should halt any racking.