Reviving a dead couch

Our much loved leather sleeper sofa had become so saggy our backs got sore and we could barely get out of it.  We added a sheet of plywood under the cushions to firm it up but then it was like sitting on a brick.  We eventually realized the problem was the cushions had worn out.  The solution was replacing the foam inside.  It’s possible to buy foam already cut to size and even wrapped with a batting which protects the foam and fills out the cushion nicely. However ordering those requires exacting measurements and can cost over $100 per cushion.  I chose to buy one large piece of foam and a separate roll of batting from The Foam Factory for $80 total to my door. This made 3 cushions with some foam left over.  One complexity is knowing which foam to pick, there are many options with different firmness, longevity, and materials.  I guessed we wanted a medium firmness (36 lbs ILD) and did not need high quality as this would become secondary seating.

I cut the foam with a bread knife and followed their directions on stapling the batting.  It took simple tools and a couple hours but now the couch is like new.  One trick I learned is rolling the cover off the old cushion allowed you to easily unroll the cover onto the new cushion without having to fight to stuff it in smoothly.