60" Vanity with granite top

[Paul Simmel]

Here's the vanity we want from the Potterey Barn Catalogue. The pic' shows marble as the top, but we are doing granite. Ours will be 60",and it's is a long span.

The top drawers are obviously dummies due to the sinks.

Something structurally beefy must be behind those drawer fronts to keep the peice from sagging in the middle over tiem, thus cracking the top material.

My initial plan we to use laminated 3/4' BB ply as a rail for the front. I don't not want to add a third leg.

The shelf below CAN have a hidden foot in the middle and back a bit so as to not be easily seen... plus I was going to make the shelf a torsion box. I've had great success with simply running hardwood rails as interior shelf parts, and laminating Luan skins to tops and bottoms. Light weight and strong.

Since I'm matching the color, I have both Elm and Oak left... enough of each for the project. I am slanting toward the Elm

What do you think?Master-Vanity.jpg

[Keith Cope]

Paul,

That should be a good looking vanity. Keep in mind the top drawers don't have to be dummies--the outer 2 can be flip-outs for toothbrushes, etc. The center drawer likely can be fully operable, depending on the size/placement of the sink bowls. A typically proportioned face frame will likely be plenty strong for the granite (keep in mind that with the 2 middle stiles you are essentially building a truss). If you have doubts about the strength you can always back it up with a piece of steel angle for extra peace of mind. That way you can use the elm for the entire face where it is most visible and save the BB for the back panel.

Good luck!

[Jamie Buxton]

There's a rail below the drawers which looks like it is 2" tall or so. I'll bet it is simply a 2x2 rail, but if you want enormous stiffness, you could make it a 2"-tall torsion box which is the full depth of the cabinet. It will not bend. On it, you stand internal walls which run between the drawer bays and go all the way up to the plywood which supports the granite slab.

[Paul Simmel]

Thanks for the input, Keith.

>>> My initial plan we to use laminated 3/4' BB ply as a rail for the front. I don't not want to add a third leg.

What I mean by this is I thought to create a laminated "beam" out of BB which would reside behind the top row of dummy drawer fronts. It would be strong as heck if I did it that way.

I think the sinks are too close for a functional middle drawer... but I can't swear to that! I have two tops here (one for another upstairs) and they are crated and stacked on two furniture dollies. The top in question is the larger of the two and on the bottom. I've been recovering from surgery and this week was going to be an Organize and Prepare and Cleanup week in the shop. I mention this because I don't think I can get the top (with under mount sinks already attached) uncreated. My initial recall is that the sinks were quite close to one another in relation to this design. I had long ago resigned to the fact that the top drawers were going to be dummy fronts. So has the wife... which saves me a lot of work.

The drawers are inset, Keith, so the "face frame" itself wouldn't have much structural integrity per se', would it?

You all can understand my concern about a 60" span, and a granite top that the wife picked out, and a potential crack right in the middle, right?

I single piece of 3/4" BB acting as a rail behind the dummy drawer fronts might be sufficient enough. I'd mortise it into the legs same as if it were a table apron. I thought that if I laminated two pieces together, it would be beyond strong.

I'm going to Sketchup this as I go during the design phase, but need feedback first because this time I want to draw each part separately in order to make them Components.

Keith, I like your idea of an angle iron. I'd need to get the top out of the crate first, though to consider your suggestions. Please have patience with me.

Paul

[Paul Simmel]

There's a rail below the drawers which looks like it is 2" tall or so. I'll bet it is simply a 2x2 rail, but if you want enormous stiffness, you could make it a 2"-tall torsion box which is the full depth of the cabinet. It will not bend. On it, you stand internal walls which run between the drawer bays and go all the way up to the plywood which supports the granite slab.

That's a very good suggestion, indeed! Thank you. I gotta get another cup of coffee and think about that.

[Jim Becker]

Paul, I think doubling up the 18mm BB and orienting it for maxium support will provide you a lot of strength as you develop your design. But do remember your stone top will be supported in many places and that helps spread the weight. It's not going to cause as much stress as you might at first think. Beefing up the top, back rail that physically attaches to the wall is going to provide a lot of your needed support as will the corner posts.

[Paul Simmel]

Thanks Jim,

Your advice is always appreciated. I'm hoping to do some SU work this evening.

Anyone have a problem with our vanity being 36" high (including the top thickness)? I'm 6'-2" and find that I have gravitated to the kitchen sink for brushing my teeth since developing lower back pain in my old age. (I know, this is more than you wanted to know! (smile)

[Jim Becker]

Paul, vanity height is certainly something you can customize to best suit your needs. Unless you plan on marketing the property in the very near future, there is little problem with raising it up a bit. And the particular design you are using seems like it could be "shortened" in the future if selling required it. (or you could just build a new owner a step-stool in your shop before you packed up... )

[Jamie Buxton]

Anyone have a problem with our vanity being 36" high (including the top thickness)? I'm 6'-2" and find that I have gravitated to the kitchen sink for brushing my teeth since developing lower back pain in my old age. (smile)

The usual vanity height is a compromise. It is low enough that kids can use the sink, and adults just have to bend over further. If there are no kids involved, build it as tall as you want. You can get extra storage space too, if you want.

[Paul Simmel]

Here's a .jpg and a .skp

This is obviously the carcass, no drawer fronts, etc. Now that I see it, it looks more than strong and probably some over kill.

It is proportionally correct, IMO. It's 60" wide. The Pottery Barn picture is 72". I already have a 61" top with sinks.

The left side is going against the wall, so no panel or anything special needed there.

I like to leave my diagrams white because I can see proportion better that way. I'm going to match the espresso color seen in the photo on the real piece.

Thanks for your input,

Paul

Master Vanity.jpg

Master Vanity.skp

[Jim Becker]

That's a fine structure, Paul. But put a few 3/4" ply horiztonal components along the back and front sides to provide a flat surface for the stone to be "glued" to. (usually a silicone adhesive) They also add some additional structural beneft right at the top. Other than that, I think you are "good to go"...

[Paul Simmel]

Jim, do you mean additional cross-members like the one in the middle? Like every 16" or so?

[Jim Becker]

Paul, I don't have the ablity to draw it for you right now on this computer, but I'm referring to horizontal stringers on the 60" dimenison that provide a 2" or so width of "surface" at the back and front of the vanity to both provide additional support for the top as well as a surface for the adhesive to adhere to. They are simple to insert in your design...fit them between each of the two top sections. 4 pcs of ply. If you can wait until the weekend sometime, I can draw them in for you. You can also see them if you look at my cherry vanity threads here at SMC in the carcass construction pictures.

[Sam Yerardi]

Paul,
Another approach you could consider is a torsion-box structure. It would be unorthodox as far as classic joinery, but torsion-box construction adds a LOT of strength in a small space.

[Paul Simmel]

JIm, absolutely I can wait and will thank you right now for taking the time to make this more clear to me. I think then you are suggesting doubling up the front and rear 60" rails, at least in the sense of adding some longer strips for gluing width. I can certainly wait for your comments, I have a lot of organizing to do in the shop before I will be starting this. Sam, the bottom shelf is going to be a TB. I considered another TB under the drawers, but deciding it was too much work and not really worth it. Thanks to all.