I built the three drawer sections of the base separately in the garage, and then used a hand truck to move them through the front door into the house, down the hall, and then carefully into the master bedroom. This photo shows one of the sections pausing in the foyer.
Once all three sections were lined up in the bedroom, it was time to build the sub-base (which would raise the drawer units 2" off the floor). The sub-base was made from 2x4s ripped to two-inch width, and then assembled into a grid using lap-joints at the corners and biscuit joints for the inner cross pieces. This is how the two joints were made (then glued and screwed together):
Although it was unlikely that I would need to move the base after its initial positioning (and would not be able to do so after the assembly had proceeded very far — very heavy even without the 1500 pounds of water), I decided to glue quarter-inch thick felt to the bottom of the sub-base. This would facilitate any needed sliding, and minimize scratching the bamboo floor.
I then moved the three drawer sections aside and flipped the sub-base over onto the floor, then screwed all of that together. Sometime around then, I started working on the ten drawers, doing some design work and then cutting out 20 drawer sides:
A piece of furniture this big and complex cannot just be built ad hoc; here is a photo of two pages out of at least a half-dozen design drawings. It's of course not necessary to make these pretty and to scale if you're just doing them for yourself, but all the parts need to be there in their proper location, and the dimensions need to be correct and consistent.
Waterbeds are filled with hot water, maintained at a constant temperature with a heating pad that sits underneath the mattress and controlled with a thermostat. If the water was room temperature, you would freeze, as the 70˚ Fahrenheit water would suck the heat out of your body. So hot water (85˚ or whatever you choose) in the mattress. But you don't want to heat the whole house, especially in the summer; you want the heat in the water to stay there, which means insulation.
On the top of the mattress, you can use a comforter or something like that. On the bottom, I am installing one-inch thick rigid foam insulation. The foam will go between several sleepers/stringers, installed on top of the three drawer sections:
Once the foam goes in, another layer of 3/4" plywood goes on top of the foam, which will then support the waterbed mattress. Before that is installed, the outer sides were installed. The plywood sides sit on maple trim pieces installed first — glued, nailed, with aligning biscuits. The outer plywood sides are glued and screwed on.
The maple trim supporting the plywood looks like this:
The plywood sides were supported vertical by temporary brackets until the glue dried:
So I end this post at this stage, with the outer sides in place:
Next the rigid foam will be installed, with 3/4" plywood going in on top of that. The lower drawer sections will get trim that will add another 3/4" to the outside of that lower layer. The upper sides (which will contain the mattress) will ultimately be three inches thick; there will be another 3/4" plywood inner side added, separated by 1.5" spacers. The sides will be capped by 3.5" wide maple, a reasonable width to sit on (hopefully that will work out).
And then of course I need to build the ten side drawers, and the long one on the end. Always the drawers . . .
