Hi Phoenix and Lucky8926,
I was inspired by Lucky8926 to build my own two-piece California King foundation, to be put directly on my metal bedframe. I had been using an innerspring mattress and boxspring for the last ten years which was recently giving me lower back pain, and I wanted a foundation that would be suitable for a latex or other foam mattress (the boxspring actually had springs in it and the gaps were too large for a latex mattress). When I started looking at my options commercially, they seemed either kind of cheaply made or awfully pricey. So I decided to build my own. Since I’ve been reading this site for a while, I thought I’d post my thoughts for the next person who looks at this thread.
Since it is a California King, I built it in two pieces so I could move it. The materials are:
i. 2x10s for the four sides of both pieces (a total of 8 pieces since I built the foundation as 2 pieces)
ii. 2x4s to form a lip on the inside of the two long sides of each piece, set 3/4 inch down so that the 1x3s would sit flush with the top of the 2x10s. I did this in lieu of a router, which I don’t own (more on that below).
iii. 1x3s for slats across each of the two foundation pieces
iii. 2x4s framed length-wise under the middle of the slats (a total of two 2x4s for this) for extra support
iv. Corner brackets purchased from Lowes, similar to those shown by Lucky8926
v. Framing screws (2.5 inch) to hold the 2x4s for the lip to the 2x10s. I purchased them for $11 for 50 at the time on Amazon here (the price seems to have gone up to something ridiculous now)
vi. Countersink set (via Amazon here), which I didn’t own (but seems generally useful) so I could countersink the screws that hold the 1x3s to the 2x4s.
vii. Small screws to secure the 1x3 slats to the 2x4s (via Amazon for $5 here).
viii. 2x4 hangers from Lowes (4 total, similar to Lucky8926’s picture)
ix. 1 3/8" lumberlok contractor screws (purchased from Lowes, though I think Amazon probably has a better price). These were used anytime I had to screw a bracket into just one 2x10 or 2x4.
I think that’s everything. I attached some pictures. Basically, I first used the 2x10s to put together the frames of each piece using the corner brackets, setting them on the metal bed frame to help me get them square. Then, I removed each piece from the frame and screwed in the 2x4s to the inside (lengthwise) to form a lip (I did this instead of routing the inside edge of the 2x10). Then, I screwed the 1x3 slats in, using pieces of 1x3s as spacers to get the slats evenly spaced. I used the countersink to pre-drill the holes to ensure that I would not split the 1x3 and to ensure that the screw head sat below the surface so as not to snag the mattress. Finally, I flipped the whole thing upside down and framed the two 2x4s lengthwise under the middle of the slats on each piece, just as Lucky8926 did.
In all, the materials cost around $150, which is less than the cheaper foundations you can buy, and a whole lot stronger. Since I used pieces of 1x3s as spacers, the slats are 2.5 inches apart. I do have a few comments:
a. Be warned: each of these pieces is heavy. I was able to move each one onto the frame, but I didn’t have to move them far since I built it in the bedroom. It’ll take two people to move each piece when we move. On the plus side, no matter what you do on the bed, this foundation is not going to break or bow.
b. I had Lowes make the cuts on the 2x10s. I could have cut them with my circular saw at home, but it would have been harder to make the cuts perfectly square, which is helpful when putting it together. It also enabled me to buy longer 2x10s to save money given the lengths needed, which would have been a pain to get home in the bed of my truck.
c. All the fasteners I used were probably overkill, but particularly the ones to hold the slats in place. Finishing nails (or even glue) would probably work, but I didn’t want to use nails because I wanted to avoid squeaks at all costs.
d. If I did it again, I would have bought a router and a router table, so that I could do what Lucky8926 did instead of using the 2x4s to form the “lip”. But I wanted to make the 1x3s flush with the top of the 2x10s for the same OCD reason as Lucky8926 did (I was also a bit worried the slats would snag the bottom of the mattress if one just laid them on top of the 2x10s). The reasons I would have bought a router include i) the elegance of that solution, ii) it’d be a cool tool to have :), and iii) it would have reduced the number of 2x4s needed by four (plus the heavy screws I used), which would have made the whole thing lighter. But my wife thought it was silly to buy a router for the job. But like I said, if I did it again, I would have bought the router anyway :P.
e. Once I was done, I realized I easily could have done just a little more work and made the entire bed (with legs and bolts or a bit more lumber to hold the two pieces together), rather than use the typical metal bed frame. But this also works.
I’d say it was a fun and satisfying project. Of course, I’m still sorting out the bed selection issue - at some point I’ll make another post about that.
This is my first post, so I apologize if I screwed anything up. In particular, I’m having a hard time getting the pictures to show up…
Okay, thanks to Phoenix’s comment, here are the pictures: