1st time cabinets - should have posted before starting

Hey Creekers-a true newbie who has been reading a lot but then seems to be replicating newbie mistakes.

Anyway, I am building 1st set of cabinets - more like set of low bookshelves, with tabletop, then shelves or cabinets on top. While I wish i could have thought of this earlier, I hadn't provided for wood movement in my initial designs. But after perusing lots of posts I have figured out this is pretty important.

My problem is that while I would like to have the cabinet top fixed only at 1 rear position (to allow float towards the front with seasons), I am worried that w/o any lateral support closer to the mid section, the upper cabs will lack structural support.

So here is my idea:

1) general picture showing cabinet, and fixed walls etc.
2) specific solution: fixed pocket screws on rear, just one set a few inches closer to front, and then figure 8 or more likely slot attachment for table top at midpoint of 12" deep countertop.

I am sure I am doing a horrible job of explaining. But if it makes any sense, please let me know if you think it might work!

Thanks All!

Tim Cleary

Tim, I am having a little trouble grasping the concept, and you may also want to tell us more about the material you are using.

Good point...if its plywood, you may not have to worry about wood movement to much.

The tabletop is pine, ripped & glued to make 13" deep top.

I guess the easiest way to describe what I want to do is that the top will be fixed to the cabinet along the rear, and along the front there will be a screw in a slot so that it can move back & forth seasonally.

Tim

If you've made the table top from solid lumber, what have you made the cabinet walls from? If they're pine too, and if the grain direction is up-down, you're home free. They'll expand and contract the same way the top will. You can fasten them together firmly without fear of joint failure.

Tim,
with a 13" deep top you are talking about a max of 1/16" - 3/32" of movement from summer to winter. Your solution should work fine. A couple alternatives would be to use buttons to attach the top (see attachment) or to simply screw the top to the cabinet from underneath using slightly larger pilot holes in the cabinet piece to allow the screw to wiggle back and forth a little. Also, you could attach the top to the base in the middle of it's width and not worry about the 1/32" or so it may move between that point and the edges.

Hope this helps,

Roger

Tim - One other comment in addition to those already expressed (that you don't have a lot of movement to deal with anyhow) - just fix the countertop to the rear as you'd planned, but fix the front to the inside front of the lower cabinet with slightly elongated screw holes, "figure 8" attachments, buttons, or whatever. Without attaching it to the front, there's a possibility that the counter will cup, which will open up a gap between the front face frame and the bottom of the counter.

In fact, you'd probably be better off running braces at 3 foot intervals front to back on the lower cabinet rather than across the width as your diagram shows. Mortise these braces into the front/back of the cabinet with glue and/or pocket screws, and fix the countertop to these at 3 points - the front, back and middle. Make the back screws fit the holes exactly to fix the back of the countertop to the back of the cabinet, and slot the holes in the braces at the middle and front positions to allow for the countertop to expand/contract.

Doing this will both solve the problem of how to attach the countertop, and keep it flat all in one go.

David - that is exactly what I will do - basically mortise a slot running back to front on the cab front top support, and screw in table top to there. Since the sides/backs are plywood, they won't move in the same way (should have mentioned that before).

Thanks everyone for the ideas. Hopefully if I keep at it I can be on the other end of these posts some day.

Tim