How to Build a Floating Vanity With Wood Slab Top
I built this DIY floating vanity as part of our Complete Bathroom Remodel project. I got some blue pine slabs from a local saw mill and thought the unique, blue stained color would go really well with the slate blue/gold tones in the guest bathroom. So, I set about turning one of the slabs, along with some oak and plywood, into a vanity.
Tools
Circular saw
Table Saw
Hand Saw
Drill
1 3/8″ Forstner bit
Random orbital sander
Angle grinder
Jack plane
Block plane
Clamps
Materials
3/4″ Oak veneer plywood
1/4″ Oak veneer plywood
2″ Blue pine slab
4/4 Oak
Wood glue
Step 1: Dimension Slab
Since the final dimensions of the cabinet would be constrained by the size of the slab, I started here, cutting the slab to rough length and width, and cutting the rough opening for the sink.
I used a circular saw with a clamped straight edge to cross cut the ends of the slab.
Then made a rip cut along one edge.
With one edge cleanly ripped, I used the table saw to rip the last edge.
Step 2: Cut Rough Sink Opening
Using a framing square and the template included with the sink, I laid out cut lines for the rough opening.
I made 4 plunge cuts with the circular saw along the straight edges, and a 1 3/8″ Forstner bit happened to match the radius I needed for the corners. I made sure to stay inside the lines by 1/16″ – 1/8″. I only had one shot to get the opening right, and I didn’t want to remove too much material.
I finished the cuts with a hand saw.
Step 3: Cut Cabinet Pieces
Now that I knew the final dimensions of the wood slab vanity top, I cut all of the cabinet pieces to size.
Step 4: Cut Rabbets and Dadoes
I prefer to use rabbets and dadoes for joinery rather than pocket hole screws. It helps square everything up nicely, makes a clean joint, and doesn’t leave unsightly holes everywhere.
Step 5: Edge Banding
I wanted the look of a frameless cabinet for this design, and, since I used plywood for the carcass, that meant covering the exposed edges. There are various ways to achieve this; I chose to use matching red oak hardwood, ripped to 3/16″ thickness.
Glued in place and secured with tape.
Since most 3/4″ plywood is actually 23/32″, use hardwood stock that is 3/4″ or 13/16″ to ensure the banding is slightly proud of the plywood on both sides. Then trim flush with a block plane or sander.
Step 6: Paint
For the vanity cabinet finish, I used a technique similar to white washing, using colored paint. I simply diluted the same paint used on the wall with water, at about a 3:1 water to paint ratio. It took some trial and error to get this right. Then I applied with a brush, and immediately wiped off with a cheesecloth. This allowed me to create a finish similar in color tone to the bathroom wall, and still preserve the natural wood grain appearance of the cabinet.
I added another trim detail on the side panels, again made from matching red oak, cut to 3/16″.
Step 7: Assembly
Provided you have cut all of your pieces and joints accurately, this should just be a matter of applying glue and fitting it all together. And clamps. All the clamps.
Step 8: Drawers
I cut all the drawer pieces to size, then cut rabbets and dados for the joinery. I applied iron on edge banding to the long edges of the plywood before cutting, when possible, to minimze the number of small pieces to deal with.
I painted the insides of the drawer pieces to match the cabinet, then joined with glue and clamps.
Step 9: Slab Work
I used a hand plane to flatten the top and bottom of the wood slab vanity top. This method is time consuming, but I find it pleasantly cathartic. I used a combination of power sanders, hand sanders, and files to shape the sink cut out.
I used epoxy to fill some holes and cracks on the surface of the slab. Then trimmed excess with a block plane.
I finished all surfaces of the slab with a rub on polyurethane. I ended up applying 12 coats, sanding with 1000 grit sandpaper in between each coat. This took a long time, but yielded a very smooth, completely waterproof finish. Obviously important for a wood slab counter top.
Step 10: Installation
When I built the bathroom wall, knowing that this vanity was going to be floating, I used 2×6 framing and marked the exact centers of studs on the finish wall so I wouldn’t have to find them later. I used 2 1/2″ cabinet screws to hang the vanity cabinet. Then test fit the slab to make sure everything was going to line up.
Satisfied, I flipped the slab over and mounted the sink. I secured the slab to the cabinet from underneath with lag screws. I made sure to drill the holes in the top of the cabinet larger than the screw shanks, to allow for seasonal movement of the slab.
Finally, I connected the drain and installed the wall mounted faucet.
Last step was installing the drawers, drawer fronts, doors, and hardware.
