Is my wall cabinet too long?

[Justin Jump]

Hey all, I got my wall/corner cabinet done last week, painted and installed over the weekend.

The wall cabinet itself is 36” long, I am betting that my shelf will sag in the middle.

My options are to double up the ¾” shelf, or just place a simple divider down the middle of the shelf. My plan was to make up a few supports so that if I ever changed the height of the shelf, I could just easily throw in a new support.

Any other creative solutions for this?

THX

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[Joe O'Connor]

1 1/4 inch cleat glued to the front edge of the shelf and a row of shelf pin holes up the back of the cabinet. Or who cares if it sags a little behind closed doors.

[Robert Engel]

I think 36 is a little long, but I've build them before.

I put a 1 1/4" wide X 3/4 thick cleat on the front if painted I just glue, screw and plug.

Other option is install a divider.

[Jim Dwight]

Play with sagulator some. If you assume 30 lbs/ft load (90 lbs on a shelf evenly distributed) I get .11 deflection for fir plywood with no edging. You can cut that to .09 with a 1 inch edge piece 3/4 thick. If you were to switch to poplar deflection goes to .08 with no edging and to .06 with one 1.25 wide edge piece. It is very easy to play around using materials you have or can easily get until you arrive at something you want to build.

I tried other hardwoods and didn't get much difference. Silver maple was greater deflection than poplar. I picked poplar because it paints well and is inexpensive. I would be thinking of hardwood shelves for that cabinet and either 1 inch edging on both sides or 1.25 edging on one side (they have about the same effect).

Height of the edging material makes a big difference. It gets raised to the fourth power in the deflection calculation. Thickness is not as important. Material is quite important because that determines the modulus of elasticity. I at least used to be able to do all this without a handy calculator - the sagulator - but it takes a lot more time and when you have an easy tool to use, why not?

[Prashun Patel]

Options I'd consider:

vertical divider
Thick edge band
Cleat at back

You can use any one of these. It's an aesthetic choice, IMHO. The stakes aren't high, tho. If any (or none) of the situations work, then you can always add more cowbell after installation. So much will depend on how you load it.

[mreza Salav]

This is what I did for our 36" wide cabinets. There are shelf hole pins on the back of cabinet as well as back of the vertical support.
You can still add the vertical support (dowel the top and then screw from the bottom):

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[Jerome Stanek]

why not add a center divider. You could drill dowel holes in the top of your cabinet and srew from the bottom to keep it in place.

[Dave Novak]

Assuming the underside of the shelf board isn't view-able to anyone who isn't on their knees, you cold locate the stud closest to the center of the shelf and put a pocket hole screw into it from the underside of the shelf. I ran into a similar situation with my garage shelves, and this worked. I actually put a pocket hole screw into every stud.

[Brian Henderson]

I've done crazy things. On a really long span with plywood, I routed a deep groove and epoxied in a steel flat bar in the center of the shelf. That sucker is never going to sag and since nobody sees the bottom and the shelf was painted a dark color, who cares?

[Mark Rakestraw]

Hi Justin, This isn't what you asked about but is the back side of the cabinet going to have doors or a plywood back? If you have doors all the way around, which is very nice for access, there is nothing to keep the cabinet from sagging. The outside edge needs support of some sort. I just installed a similar cabinet but it was full height and I screwed into a ceiling joist at the outer edge. You'll need come up with some way to tie it in to the ceiling or it pretty much has to sag. The most inconspicuous might be a metal rod that matches the finish on the hardware you choose.

Edit: Ah, at first I didn't see that there was a soffit, which I assume is 12" deep or so. Assuming you can fasten into that near the outer edge that will help a good bit. If your design had substantial top rails, maybe 4", then I would be comfortable that it could support itself. Without that I still think there is a pretty good likelihood that it will sag without support. Assuming overlay doors you could use 4" top rails and still have equally height doors all the way around. You would see the wider top rails when you opened the doors.

[Jim Neeley]

Depending upon the strength you desire, you could do as others recommended and place a piece of hardwood .75x1.5 and mount a piece of angle iron either .75x.75.1/8" thick or 1/2x1/2x1/8" thick hiding behind the hardwood, glude and screwed to both the shelf and hardwood. Between that an a row of shelf holes along the back you could really load that thing up!

[Justin Jump]

Great eye Mark.....

I had thought about that, I have a couple reasons/solutions.....

Being that "most" of the stuff on the corner will be localized to the lazy susan, its attachment point is closer to the center of the cabinet, so I don't think there should be too much weight towards the end of the cabinet.

For the weight of the cabinet itself causing some sag, yes, I do have it anchored into the bulkhead right at the 12"mark.

Finally, not shown yet in the picture, is the way I plan on running my crown molding. I want to keep it simple since they are shaker style cabinets, and I was planning on just running a simple, straight, flat piece (a question I am soon going to post to the forum) up from the cabinet face frame to the ceiling.

This simple crown will help anchor the front of that corner cabinet to the crown which will be tied into some support hidden behind. This will also hide the rookie mistake I made of running the can light too close to the cabinet, traditional crown will interfere with the light, but I do have about 3/4" to play with before I interfere with the ring of the can light escutcheon.

[Mark Rakestraw]

It sounds like you have it figured out Justin. That should work fine.

[Peter Quinn]

We have had good success laminating two pieces of 1/2" plywood to make a 1" thick shelf, these hold up pretty well to about 42". I like the rear shelf pins at the center line assuming you have 1/2" backs, with 1/4" backs probably not enough material to do much but it might still help. Once you pick a height for the shelf you might be able to tack a small inconspicuous cleat of the same finish under the shelf at the back at the mid span to avoid sag.

[peter Joseph]

How about a lignum vitae shelf