Expandable Folding Foam Bed/Sofa Platform for Teardrop Camper

I bought an awesome little teardrop camper (Runaway Camper) and it's amazing. I opted for the folding Foam Sofa/bed that the manufacturer offers as an add-on. In the ad photo above, you can see how the head doesn't fold flat, which is quite uncomfortable when trying to sleep on it. We tried stacking pillows up, and even tried to use the rounded hump as a pillow, but it just wasn't working for us. I think the matress is comfy, so I didn't want to try to find a replacement and scrap the whole thing. I played around with it and decided to build a 5" riser that would sit under the main part and allow the 'head hump' to fold downward, leaving the flat back side up and level. The height is perfect for 2x4s since they are 3 1/2" wide and 1 1/2" thick, equalling a perfect 5". Ideal for this use since they are cheap and sturdy. I considered thinner cuts of wood, but it would have been far more expensive and unnecessarily complicated. This project effectively expands the bed from 64" of flat surface to 72", so I started researching and thinking...

Supplies

Qty 6 - 8' 2x4's
A 43" x 6" plank ($7 at Sutherlands for a poplar piece that was 48" x 6")
Screws (I already had a pocket screw jig and 1 1/4" pocket screws, but decking screws would also work)
Wood glue
Square
Carpet remnant (for front cover, mostly for aesthetics, but also to help glide smoothly on the bottom that will be on the floor)
Hammer-in Felt foot pads (to prevent marring the linoleum floor)
Staple gun (to attach the carpet to the front plank
Scissors
Box knife
Jigsaw
Chop saw
Sandpaper

Step 1: Measure and Cut Wood

Prepare all the wood pieces:
Cut 11 pieces of the 2x4s in 32" lengths using the chop saw (planks for mattress surface to sit on)
Cut 2 pieces of the 2x4s at 43" (front and back)
Cut 4 pieces of the 2x4s at 19 1/4" (inside cross braces)
Cut 3 pieces of the 2x4s at 30 1/2" (sides and center)
Cut the front panel (1/4" material) at 43"
I used a jigsaw to cut a 45 degree edge for the 5 slats that will be sliding in and out to help guide them into place.

Lay all the pieces our upside down and double check your measurements. I wanted to leave a little space between the camper walls and the platform, so I made my width 43". I recommend sanding every surface to remove potential splinters and snags.

Step 2: Glue and Screw

Assemble the frame parts first, checking that everything is square, then move to the slats, then the front assembly of the slats. You'll want to lay it out first, then assemble it after making sure everything is the correct length. I found that the pocket screws are ideal for this project since it allows you to build it from the bottom side and ultimately hides all the screws when it's in use. Also, there are no screw heads on the top to snag the mattress.

Step 3: Finish Up

I sprayed some polyurethane on mine to protect from water, mold, etc. since this will be in a camper. I covered the front plank with black carpet so it blends in with the sofa color, then used sheetrock screws to attach it to the front. Be sure to raise it about 1/4" off the floor so it won't catch on anything. Hammer in the felt feet on the bottom parts that touch the floor.