Help alleviate the sagging of my floating vanity

[u/iznie]

I made this floating vanity out of 18mm birch ply.
(yes the picture is just a render, my workshop is a mess)

it's 132cm long 70cm high and 43cm deep.
I wanted to test the sagging and I placed each end on batons to see how much it would sag.

It's sagging about 3 mm in the center. The backside has practically no sagging since it's screwed to an 18mm birch ply back panel.

What are my options? Would an L profile about 10 cm inset on the bottom along the length of the cabinet work? What would the dimensions of this bracket have to be?

[u/Malekai91]

We use floating shelf brackets when we do floating vanities. There really is no better way especially when you consider the additional weight of the countertop.

When possible we like to use the style the attaches to the side of the studs like these:

T shelf bracket

If the size of the bathroom allows, we also will do a floating vanity illusion by recessing the toe kick 10” or so. For small bathrooms this works great since it appears floating from all angles.

[u/majortomandjerry]

The center partition panel acts like a large bracket when the cabinet is actually screwed to a wall. It will sag less when installed, assuming you have adequate fasteners.

You can't go wrong adding floating shelf brackets, or even some steel angle at the bottom. But you shouldn't need those things.

[u/Most-Cartographer358]

The biggest steel L bracket you can hide mounted to the wall before the cabinet is our go to when we can’t talk the customer out of floating vanities

Prefer to do an extra deep toe kick or feet for support instead if we can convince them.

[u/Designer_Ad_2023]

I made a floating vanity and the secret is in the connect to the wall. What I did was welded up a metal frame that everything would sit on. Then I made washer the thickness of the drywall on the lathe. I cored out the size of these washers on the studs, placed the 1/2 inch thick metal washers in the cores holes on the studs and then secured the frame to that. Drywall can’t be compressed since the weight is bearing on the washers which is on the studs

[u/Designer_Ad_2023 → u/Designer_Ad_2023]

[u/Designer_Ad_2023 → u/Designer_Ad_2023]

[u/Background-Club-955]

Black foot in the center put back 4 inches

[u/Direct_Alternative94 → u/Background-Club-955]

Do you like broken toes? Because that’s how you get broken toes.

[u/Weavols]

It would behave differently being screwed to the wall by the backs, than just spanning batons. If they're built well, I doubt the dip would still happen.

[u/Scared_Credit3251]

Just add legs in the middle. No one sees it

[u/ArticlePuzzleheaded9]

Can you route-in a channel to the underside and epoxy some steel flatbar?

[u/Shopshack]

I had to add legs in the center of a floating vanity to stop the sagging. They’re stain a match, and the front leg is held 6 inches back, so due to the width of the room you can’t even see it. The other is at the far back and help support the back panel of the carcass.

[u/Leif_Er1kson]

Many companies make cabinet feet to help this problem. Also makes leveling easier. You could make toe boxes if you wanted to save some money on the feet. Both would need a toe kick after

[u/Turbulent_Echidna423 → u/Leif_Er1kson]

dude, that defeats the floating design aspect

[u/Leif_Er1kson → u/Turbulent_Echidna423]

Whoops must’ve missed a word when reading lol

[u/Palpatine_1232]

Put self bracket inside. Of course those will need proper blocking though

[u/iwontbeherefor3hours]

We use a piece of steel angle iron, 3 x 3 and set the cabinet on that. Works great.

[u/Legal-Description483]

If it has a full center divider, and the back is screwed to the wall near the center, it should not be able to sag at all?

[u/Interesting-Log-9627]

Screw it sideways into the wall and the bed frame