Table leg / Movement question

[Craig D Peltier]

A client of mine wants a table with the leg coming through the top. Ive done this before and I left a 1/4" gap around both sides of each leg that were enclosed by the tabletop for wood movement. I understand I only need to leave one side but this client has asked me if I can make the legs tight to the top? I told her I didnt think it was a good idea due to the expansion of wood.
There will be an apron underneath it, the table will have two leaves that are 18 inch wide each. The top is 40x70 w/o leaves of 1.25 thick ASH.

Also if anyone knows wood movement of KD ash that thick over 40 inches that would be nice.

Thanks

http://www.sawmillcreek.org/showthread.php?t=55418 Heres link of the table legs im talking about. This will be same table but with leaves out of ash.

[Jim Becker]

Personally, I think that the table will get into trouble without having the gaps for expansion across the grain on the top, especially with that width. Suggest to the client once again that you don't recommend that due to the fact that it could result in cracking. If the client still wants that, they should be willing to sign a written statement absolving you of responsibility for any cracking due to that request. IMHO, of course...

[Steve Schoene]

The key to making something like that work is to allow the legs--which would move with the table top width to move relative to the apron instead of the usual way where the apron and legs are fixed together and the table top width moves relative to the underpinnings. That presents some interesting engineering problems, but think of the table top and legs without any apron but with the legs firmly attached to the top. The apron then becomes a decorative attachment, and the top the structural element.

Another way around this is to make the top with a veneered material that avoids the movement issue that way. You can find or make "real veneer" that is substantially thicker than the micro-veneer on plywood. Of course, this changes the method of working quite dramatically.

[Chris Friesen]

A client of mine wants a table with the leg coming through the top...this client has asked me if I can make the legs tight to the top?

There will be an apron underneath it, the table will have two leaves that are 18 inch wide each. The top is 40x70 w/o leaves of 1.25 thick ASH.

What about breaking with tradition and running the grain across the table? That way you could set it up so that all the expansion happens towards the center...where it already expands to accept the leaves.

Alternately, put a gap down the center of the table (possibly with a decorative motif of some sort) such that the grain is lengthwise but the expansion happens towards the center. This was discussed in FWW...can't remember the issue though.

[George Bregar]

Maybe I'm not understanding right, but simply having the legs attached to the top is not an issue. Doesn't matter how big the top is in regard to movement. The legs would not pose a problem any more than a tenon would have in a mortise.

The stretcher on the long side (assuming the grain is also oriented that way) could also be glued...M&T. The only issue is the cross grain stretcher. Only think of there is slip wedge tenon. And then could have sliding dovetail connection to the top, which would prevent racking.

But I think in general I would tell the client that there is a reason this in "unconventional".

[Dick Bringhurst]

I agree with Steve. Design it so the end aprons expand with the top. Dick B.

[Bill White]

Why not show a "false" leg on the tabletop? Just a relatively thin slice of end grain that could be perceived as the end of the leg.....Inlayed into the top.
Bill