A C-frame futon bed looks much like a standard bunk bed. However, it has a folding, full-size futon couch in the bottom position rather than a flat mattress. It gets its name from the C-shaped gaps in the end frames that offer armrests for the people sitting on the couch. Although the specific assembly method differs by manufacturer, the general process is fairly consistent. Set aside an hour for this project which, in most cases, requires only basic home tools.
Lay the back and seat of the lower futon on the ground with their open ends meshing together. Connect them in place with the sliders and cotter pins that came with the C-frame bunk bed kit.
Attach one of the couch spacers -- the long beams that support the edge of the frame -- to one of the end frames with a bolt. Use a hex wrench and a crescent wrench to tighten down the nut 1/3 to 1/2 the way.
Attach the other couch spacer opposite the first with the wrenches. This step is much easier if you have an assistant hold the end piece in place.
Set the top bunk mattress support in place at the top of the end frames. Bolt it in place as you did the spacers.
Slide the futon couch frame in place at the bottom of the end pieces by maneuvering the sliders into their grooves.
Tighten down all the bolts completely.
Set the futon mattresses in place on their respective frames.
Attach any extra components, such as safety rails or a ladder. Although installation methods will vary, they will usually be very similar to how you attached the main components.