This is a great start. The fix for a saggy mattress:Meliusly Sleeper Sofa Support Board This support board stiffens a sagging mattress and folds flat for storage in the bed or beneath the cushions ...

Two things can be true at once: Sleeper sofas are a feat of engineering, and they can be the bane of your existence. It’s a marvel to fit a frame and mattress for a bulky piece of furniture ...

Even though it's hiding a full queen-sized mattress inside, the sofa is impressively compact—the most functional option for ...

Aside from this top-rated cozy memory foam number, we found two close runner-ups for the best sleeper sofa mattress.