Does your RV suffer from a sagging tri-fold sofa bed mattress? This simple, inexpensive fix could be the cure.

By Chris Hemer
photos by author

t was probably around two in the morning when I rolled onto my side and heard creaking beneath me like the sound of an old rope about to give way. This was followed by a few small pops — then it felt as though my hips were slowly sinking lower into the mattress. I woke up a few hours later in a position not unlike that of a person who is floating gently down a river in a large inner tube, with my hips seemingly sinking below my knees. Except, I wasn’t in an inner tube, I wasn’t out in the sun, and I definitely was not having a good time as I extricated myself from the shallow breach the following morning.

What happened? Like sofa beds used at home, tri-fold couch beds in RVs offer serviceable temporary sleeping accommodations when guests stay over, but they make a better sofa than a sleeper — and, apparently, the tri-fold unit I’d curled up to sleep on the night before had reached the end of its lifespan. I pointed out the unfortunate depression in the mattress to RV Enthusiast magazine’s Technical Director, Chris Dougherty, who frowned and said, “Well…that doesn’t look good, does it?” As a RVIA/RVDA certified Level 2 technician with an impressive array of tools, Chris got right to work disassembling the troubled tri-fold.

This RV tri-fold sofa bed in a 2015 fifth wheel provides plenty of seated support, but as we discovered its secondary use as a temporary bed apparently had a limited lifespan.

What we found was, well, unanticipated. Instead of using springs or metal bands to support the tri-fold’s center section, it was fitted with nylon packing straps (akin to the type you cut off a household printer/copier box before you open it). Not surprisingly, these straps are designed for temporary use, not supporting someone’s backside for the long term. With a few years on them, the straps had all stretched — and on the side I had been sleeping on, they had snapped. Thinking quickly, Chris devised a plan: Fit the bed frame with real nylon straps that could support the weight of a human weighing more than, say, a household printer/copier.

Happily, the job took about an hour and cost around $20 for the nylon strap and hardware. When finished, the repair worked perfectly and has lasted for several weeks so far with no problems. Here’s how we did it.

One of the big differences between RV and household furniture is light weight, and ease of assembly for mobile appointments. These tri-fold sofas can be easily disassembled in sections by pulling clips that secure the frame to pins.

The first step is to cut away the remaining straps with a box knife.

Next, the frame was wrapped in a zig-zag pattern with 1-inch wide nylon strap, which is available through Amazon and other retailers. While pulling the strap taught, a self-tapping screw was run through the strap and into the metal frame. If the strap grabs the screw as it is inserted, use a piece of duct tape over the strap before drilling. You may also elect to use small washers underneath the screw heads to increase clamping force.

Once you are at the end of the frame, use a box knife to cut away the excess strap.

The foam padding is reinstalled in the frame and then worked back into the cloth cover. Close the zipper, re-install the section on the pins and the job is done.