Solid oak on top of plywood box?

[Rob Price]

I am building some modular storage for my sons' room. 29x20x15 bases with drawers and square shelves on top. See the diagram.

The bases I'm building are basic 29"w x 15"tall x 20" deep boxes. They will have a single drawer in each unit. The sides are going to be plywood, but I wanted to make the top (20x 29) out of solid oak because the boys will be playing/climbing/banging toys etc and I'm afraid the veneer just wouldn't hold up to that kind of abuse (although with some poly, their existing plywood funiture has held up for the last 2 years.)

my concern is wood movement, and attaching such a wide top to the box. I had planned on running some shallow rabbets on the edges of the top and then gluing the top to the box (I'll be hiding the joint with some molding), but with the grain running side to side, the top is going to need to expand and contract front to back. Gluing the entire joint is probably not a good idea. I thought about pocket screws front and back to keep it secure, maybe one in the middle. Or do I just scrap it and use plywood for the tops and a generous coat of poly. this isn't fine furniture, it's a storage unit for their toys.

[Bill Orbine]

"although with some poly, their existing plywood funiture has held up for the last 2 years"........why not simply glue hardwood edges to the plywood top? I'd be concerned about the expansion and shrinkage, too, and what I'm suggesting seems to fit the bill for me.

[Danny Hamsley]

I would consider attaching the tops with the z-shaped table top fasteners. You cut a biscuit slot in the plywood side for one leg of the clip and screw the other leg to the top. Then, if the solid top moves with the season, the clips allow the top some freedom to move because the side leg of the clip can move in the biscuit slot. Here is an example of a table top fastener that you can get from Rockler.

http://www.rockler.com/search_results.cfm?filter=table+top+fasteners&submit.x=24&submit.y=4

[Vince Shriver]

I'd glue and pocket hole nail strips flush with the top edges of the ply boxes and screw the top onto that (slotted holes in the nail strip to provide for wood movement).

[Jamie Buxton]

You're right, attaching the solid lumber top firmly to the plywood sides is a bad idea. However, while you say that the top is 20" deep, the drawing shows that only the front five inches or so is visible. You could get away with gluing five inches of lumber to plywood. So use solid oak where it is visible, and plywood further back, where it will be unseen anyhow. Or tweak the design, so that there is a top to the lower boxes only for the front five inches, and the cubbyhole floor rests directly on the sides of the lower boxes; that is, there would be no step up at the rear of the five inches of solid oak.

[Rob Price]

It's about 7 inches in front, but I had not thought about that... That would also mean when I wrap the bottom box with trim, it would cover the joint where the cubby on top sits on the box, interesting idea, I'll have to play with that a bit. I had thought about doing a plywood/solid wood top as well, it just seemed like a bit of hassle...

[Paul Johnstone]

Rob.. that is basically what my TV stand is.. A plywood box with drawers and a solid oak top

I attached three plywood strips across the top of the plywood box (hidden when top is on).

I used screws in the middle strip without making the holes longer. One the two side strips, I made the holes slightly elongated to allow movement.

I always though that you were supposed to firmly fasten down the middle of a solid wood panel and then allow the outside edges to move.. I did not do this once, and the wood panel bowed in the middle over time:(

Obviously, wood moves acrosss the grain, so my plywood strips are laid out that way (the strips run the length of the wood , like the tree grew verticals).. Sorry, I am not speaking clearly.

[Rod Sheridan]

Sliding dovetail, glued at the front edge only..........Rod.

OK, forget the above answer, I thought that there was some overhang on the top, so that wouldn't work.

As another poster indicated use a rebate on a plywood top with wood edging.