Sofa springs can wear out before a sofa has seen the end of its days. For sagging springs in a sofa, you will need to fix the offending spring in order to prevent further damage to a sofa. Without proper attention, one broken spring can lead to holes in sofa fabric resulting in a decidedly unattractive appearance, making it necessary and unavoidable to replace the sofa outright. Before this happens, fixing a sagging spring is a quick and easy home repair.
Turn the sofa on its side, giving you enough room to work with the bottom of the sofa.
Remove the gauzy fabric covering the access point to the springs. Some sofas have this attached to the sofa bottom with hook and loop tape, while other sofas have the fabric stapled into the base. If attached with hook and loop tape, simply remove the backing. If the fabric is stapled to the base, use the pliers to remove the staples without damaging the fabric. This gives you the ability to reuse the fabric.
Find the offending spring. Sagging springs are a result of using one side of a couch more often than another. In some cases, one of the springs may have come lose. If springs are disloged or loose, snap them back into place. Once in place, tighten the clip holding it to the base with a drill. If the springs are sagging due to wear and tear, unscrew the clips holding the spring in place on either end of the bottom and flip it over. Screw the clips back into place with the drill.
Replace the fabric on the sofa by reattaching the hook and loop tape to the base or stapling the fabric to the wooden base with a staple gun. Once you flip the sofa back to its original position, the sag should be gone.
You can reinforce some springs with twine, by tying the twine around the sag and attaching it to a stronger spring or the sofa base.
Never try to reuse a completely broken or damaged spring.