How to Fix a Sinking Couch Cushion

Remove all of the cushions from the couch and push down on the springs. The springs should come back up quickly and move back to the same level they were. If the springs do not respond as they should, they could be worn out. In that case the problem is the couch itself and not necessarily just the cushions.

Flip the two end cushions to the opposite ends of the couch, if they are the ones causing the problem. Flip the middle cushion upside down if it is the one that is sinking. Couch cushions tend to develop flat spots and sinking areas from use, and flipping them can give them more spring.

Remove the cushion from your couch if it is still sinking, even after being flipped. You will need to remove the foam insert from the cushion and replace it with a new one.

Unzip the cover from the couch cushion and remove the foam insert. Lay the cushion cover out flat to smooth out all the wrinkles, then measure its length and width.

Add 1 inch to your measurements when ordering replacement foam for your cushions. Add 1/2 inch if the cover has ears which fit over the seams.

Measure the thickness of your existing cushion and order a new foam insert based on those measurements. Round down to the nearest inch if the difference is less than 1/4 inch. Round up to the next inch if the difference is more than 1/4 inch. For instance, if your existing cushion is 5 1/4 inches, round down to 5 inches. If the cushion is 5 3/4 inches, round up to 6 inches.

Insert the new foam insert into the cushion cover and zip it shut. Replace the cushions on the couch.