About three weeks ago I drove up to see my parents, and they had two extra twin sized mattresses, which I politely took off their hands.
I then set about building a bed frame that fit the size of the mattresses perfectly. It took all of three hours and cost me less than $30 - $28 and change to be more exact.
I should have taken pictures while I was building it, but you should get the idea - it's VERY simple.
The frame has not been stained, painted, or any of that. If you want to spend an extra $10, you could easily make this look very nice instead of just a wood platform for a bed frame.
Step 1: Getting the Sizes and Materials
I'd say give an extra inch all around the edges so you make sure you have plenty of room for your mattress.
After measuring my mattresses, I ended up with 75" wide, and 74" long. So the frame was built to be 76" wide and 75" long.
You'll also need to decide on a height. I opted for 10" high legs.
For materials I used...
6 2"x4"x96" planks
1 1/2" plank of plywood
1 4"x4"x8' plank
A handful of 2 3/4" nails
A handful of 1 1/2" nails
I had the plywood and 4"x4" planks sitting in my garage from whoever lived here before me, and they worked great.
You could get all your wood for free on Craigslist very very easily - just toss up a post in the wanted section for scrap wood. You may end up needing to piece things together this way, but you can make it happen pretty fast.
I also bought some angled brackets, but realized I didn't actually need them when I started nailing things together. For extra support, you may want some though.
Step 2: Cutting to Size
I didn't have any saw horses, so I used two broken speakers I had sitting around to support the wood as I was cutting it.
This process took about 30 minutes total. Not too bad.
Step 3: Building the Frame
Using the four outer pieces of 2x4, I simply nailed them together to make a box.
When that was done, I measured the space between vertically so I could cut the support beams to size. One had to be recut because I was a hair too long, so make sure to measure twice so you don't end up with one too short.
After nailing these in place, you can work on the legs.
Step 4: Putting the Legs in Place
The legs needed to sit in the corner, but there wasn't really anything stopping them from bouncing backwards so the nails could go in.
That meant the legs kept getting pushed outward when I'd hit the nail, and I'd have to whack the wood back into place, therefore knocking the nail back through it's hole.
I tried to put my foot behind it to keep the wood in place, and it helped, but it was still a bit annoying to have to hit back and forth.
You could probably use some extra wood cut to length to place between the leg and the opposite edge and that would work nicely.
I used one nail, as you can see in the picture on each side of the legs.
This works, but when moving the bed into place, the legs knocked around a little, so I suggest using two nails in each side. I'll actually be reinforcing them today like that.
Step 5: Testing the Strength and Adding "weight Balancers"
It held up like a dream.
I decided I needed something to help spread the weight across the support beams, so I cut up a piece of plywood I had laying around (SO close to perfect length already) and nailed it to the top of the bed, as you can see here.
This helps dramatically with weight distribution.
Step 6: Putting It All Together!
I put the mattresses on top, and got everything all set up.
You can see it all here.
The only problem was that the mattresses were different heights.
I took the left overs from the 2"x4"s and tossed them under the shorter mattress and it ended up being almost a perfect match.
I'm going to get a simple foam top and toss that on the bed and it'll be like just one big mattress.
We slept on it last night and it was great. It was nice to be back in a real bed.