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How to Fix a Sagging Couch | Lim's Upholstery
There are several do-it-yourself options to fix a sagging couch. Of course, you could just throw some thick cardboard or a piece of plywood under the cushions and call it good, but this does not deliver a very comfortable or long-lasting outcome. The overall goal is to make a more stable and rigid structure, and more even and comfortable cushions as well.