Sinuous springs or serpentine springs get their name because of their "S" shape that resembles a snake's body. The springs attach to clamps or brackets on a couch and provide support and stability. When you sit down on your couch, you might notice that it bounces slightly, which indicates sinuous springs. With regular use, the metal construction breaks down. You might feel the springs poking through the couch or feel sagging. Sagging occurs when a spring breaks. Fixing the old springs on the couch restores its natural shape and makes the couch feel more comfortable.
Remove any pillows or cushions from the top of the couch. Turn the couch upside down and look at the bottom. It should feature a thin piece of fabric stapled to the bottom, which covers the frame and springs. Remove the staples with a pair of pliers and set the fabric aside.
Locate the broken or damaged sinuous spring inside the couch. Look for a missing spring, cracks in the spring or a spring that droops down slightly. The springs should run from the front to the back or from the left to the right.
Place your hand on the broken spring and trace your hand back to the starting point. Remove the screws on the bracket that holds the spring on the couch. Move to the opposite end of the spring and remove the screws on that bracket. Once you loosen the brackets, the spring should slip loose.
Insert the edge of the new spring into the bracket and attach the old screws. Pull the spring across the couch and slip it through the opposite bracket. Screw the bracket closed with the old screws and cut off the excess spring with wire cutters.
Screw a 2-inch wood screw halfway into the wood frame. Wrap baling wire around the screw and finishing screwing it down. Stretch the wire across the frame and attach to a second screw you screwed into to the frame. Attach four pieces of baling wire across the center of the springs for additional support. Cut off the excess wire with a utility knife.