Things You'll Need
After a prolonged period of time, a sofa that is constantly used will wear down and eventually begin to sit low, causing discomfort for anyone sitting on the furniture. While it may seem like the cushions are to blame, the truth is that the supportive springs below the cushions have weakened. To save money and avoid purchasing a new couch, you can fix the problem on your own. While you can't replace the sofa's actual springs, you can create a homemade, customized support piece using plywood to fix the low-sitting sofa.
Remove all cushions from the sofa.
Lay a large piece of butcher paper across the support frame of the sofa. Trace the shape of the specific sofa seat using a marker.
Cut the pattern out using a pair of scissors.
Cut a piece of 1/4-inch-thick plyboard to match the seat. Trace the butcher paper pattern on top first to ensure the measurements are perfect.
Place the plyboard directly on top of the sofa seat.
Put the sofa cushions back, laying them over the plyboard, which offers adequate support and stops the sofa from sitting too low.