Outdoor dining table top joinery ideas

[Brian Runau]

Planning on building a 4 x 4 table out of cypress. I should have enough lumber in my inventory to do a top that is 1-1/2 or 1-3/4 thick. Planning on the apron for the top to be @ 5" wide with 90 degree butt joints at the corners. Two sides will have a 48" x 5" skirt the other sides will be 38" x 5" skirt with @ 11 slats running parallel to the 38" run with @ 1/4" gap between slats. This works with the lumber I have.

My question is how to join the @11 38" x 3" slats to the 48" sides of the top. I have a domino and can let them in this way. Not sure on movement since it is outdoors. Do I mill a groove in the 48" sides and put a tongue on the 11 38" x 3" slats and put spacers in the groove between the tongue and if I do this do I glue on the tongue of the slats or let them float as well as the spacers?

Open to suggestions, looking for the best way to allow as much wood movement so I don't get cupping etc...

Thanks.

Brian

[Lee Schierer]

If the grain directions align you don't have to worry too much about dimension changes. Cross grain joints will be a problem, so you have to make provisions for expansion/contraction. Your long aprons will be a problem. You might be able to attach them with figure 8 clips. You can find figure 8 clips in stainless.

[Brian Runau]

[QUOTE=Lee Schierer;3313633]If the grain directions align you don't have to worry too much about dimension changes. Cross grain joints will be a problem, so you have to make provisions for expansion/contraction. Your long aprons will be a problem. You might be able to attach them with figure 8 clips. You can find figure 8 clips in stainless.[/QUOTE

All the slats will be cross grain. I can do a tongue and groove for those slats inside the frame and not use glue on them, Ok? Not worried about attaching the top to the base, I'll allow for expansion. How would you do the cross grain butt joints on the corners of the top? Thanks Lee. Brian

[Jamie Buxton]

Your cross grain glue joints are only a few inches long. They should fine. Glue the with water-tesistant glue. I’d use epoxy, but many folks use Titebond II or III.
I’d be a little more concerned about creating ledges or holes where water can pool.

[Nickolas Martin]

Hello!
Leave space between tongues and in grooves for thermal expansion. Do not glue the tongues completely, let them “float” in the grooves. the tree will be able to expand and contract depending on the weather.
You can also take metal corners or clamps that can be hidden inside the structure for additional strength.
I would take the finish against moisture and UV rays. Drying oil or varnish for exterior use. if you regularly update the finish layer, the table will last longer