well......

they look like lag bolts. Maybe they go into a stud (that's good) but....

It looks like the hole is big enough that the head of the bolt could easily rip through the backing plate that is attached to the wall.

AND...

the back piece might be attached to the wall ok - but how are the sides of the cabinet attached to that small back piece?

Any chance you can find the mounting instructions for this cabinet?

I wouldn't lean on this one too hard.

@just_janni Thank you.

I believe the contractor screwed into the studs, but I also noticed the left bolt could detach from the backing plate, as you pointed out.

I'm not sure how the sides of the cabinet are attached to the back piece, but they shipped pre-attached.

The mounting instructions I could find simply said to drill 4 holes into the studs and insert screws without specifying what kind of screws or how they should be oriented.

I would want 2 screws/bolts on the bottom too.

In my previous house I had a floating vanity in my master, although it did sit on small bump out against the wall, that had to be added to hide plumbing that came out of the floor. Caught my cleaning lady on a step ladder with a foot on the front of the counter trying to clean the top of the mirror! I suggested she probably didn't want to take that risk ... although my contractor swore you could dance on the floating vanities he installed! :-)

The 2 lags are enough, if they had washers. Your kitchen cabs are held only on the top rail filled with dishes or cans. Having said that, I would do 2 more lags down below too. Also, push on the front corner. If the cabinet racks, I would want a bracket on both sides (many have small plastic style if not wood) so as not to rely on the countertop adhesive.

I think a hefty washer on each bolt would be a good idea.

Thanks @chispa, I figured 2 more screws/bolts at the bottom as well, if anything.

Wow your cleaning lady sure was confident! Such an unnerving sight to behold. Perhaps she got the same memo from your contractor :)

Thank you @3onthetree @Mark Bischak, Architect

Is it ok to take the bolts out and reinstall with washers, or is it too late for that?

The hole in the wall wood framing should be good to take out and reinstall the lag bolt w/ washer in the same hole. A few times and the hole could be compromised though.

There are two washer diameters for bolt sizes. Request the larger size, a thick version or doubled. Minimal cost.

If you want more to worry about, how is the back board connected to the side panel?

@3onthetree @dan1888 Sounds good, thank you for the advice.

@Mark Bischak, Architect Right, that's an unknown to me (nothing visible I can make out). I'm hoping that since the manufacturer was the one that made that connection, it should be good enough for any reasonable weight put on the vanity.

No, it not secure enough. You need to screw corner brackets at the top and bottom:

@Joseph Corlett, LLC Wow that floating vanity is going to stay floating!

I don't know if I'll be able to do the same with mine as I only have studs to screw into, and I'm not sure they're going to be where the corner brackets would be.

It's been floating for 6 years so far. The stud location can be irrelevant. The drywall is removed where you want the vanity located and 1/2" plywood is installed to the studs wherever they fall. The vanity is attached to the plywood.

"I was standing on my vanity just like @Joseph Corlett, LLC ...."

@Joseph Corlett, LLC Solid as a rock, very nicely done! Thank you for your insight.

@Jeffrey R. Grenz, General Contractor :)

A cam lock system with dowels, which you probably have, will be stronger than the corner brackets shown above unless the corner brackets are bolted in rather than screwed in.

Of course if you mount 20 brackets into plywood and have a cleat it will be stronger, but also way stronger than it needs to be. You also don't need a plywood panel set into the drywall as long as it is screwed into the studs. Again, it is just overkill and a waste of time and money.

My lumber rack is mounted to 2x4 studs on 24" centers in a fashion similar to your vanity. I used standard 3" wood screws to mount it (not even lag bolts) and it is carrying a few thousand pounds. The studs are not bowing and it has been carrying that load for years now without a problem.

If you really want to enforce it, grab some 2" plate washers and use those instead of regular washers... or you can pay for the overkill.

@bry911 This is very reassuring information, thank you for sharing.

" Again, it is just overkill and a waste of time and money."

Until your cleaning lady stands on it.

Love this thread and have a related question. Is there a formula for how much weight from a heavy, thick marble top a floating vanity can take? Is there some system that supports the marble top in addition to the support for the vanity? The vanity top and high backsplash I LOVE looks like it will crush the 30 x 18 2-drawer floating vanity. Thanks.

@Violetta Valery -Marble just isn’t that heavy. You are talking about 80 lbs of marble and just isn’t that big of a concern assuming your vanity is constructed and mounted properly.

Your vanity needs to be mounted into wall studs somehow, but so long as it is mounted into studs with a faster that either attaches to the sides or has a decent washer, the weight will not be a problem.