Even the most well-made and cared-for sofas can sag over time, making the furniture uncomfortable to sit on and oftentimes unsightly. Rather than purchasing a brand-new item, you can typically fix a sagging sofa with minimal cost and effort. To start, remove any items from the frame of your couch and take detailed measurements of the area underneath the cushions. Then, purchase a piece of plywood in the same size and place it underneath the cushions. If the sagging is caused by uneven wear on the pads, you can typically replace the foam inside the seating or add additional foam to fix the sagging.
The first step to fix a sagging sofa is to remove everything from the piece of furniture, including throws, slip covers, and pillows. Then, remove the cushions themselves, including the back cushions if they are also removable. As you are removing the cushions, check each one for unevenness, as this will help you to determine how to fix your sagging sofa later.
Carefully measure the area on your sofa where the seat cushions rest, making sure to measure from the front of the couch to the very back. If you have permanent cushions on the back, and there is a space beneath them for the seat cushions to slide into, measure to the back of the couch underneath the back cushions. Write the measurements down for future reference.
Take your couch dimensions to a local hardware store, home improvement store, or lumberyard to purchase a piece of plywood. To save yourself time, you can typically ask a store worker to cut a piece of plywood to your desired measurements rather than cutting the piece yourself at home. If you would rather do the work yourself, purchase a piece of plywood slightly larger than what you need, and cut the piece to size at home with a table saw.
Once you have the plywood in the right size, place it on the couch in the area where the seat cushions go. If the cushions themselves are in relatively good condition, place them on the piece of plywood, flipping them to the opposite side that they were before. The sturdiness of the plywood will help to prevent the cushions from drooping, and flipping the cushions will even out the wear on them.
In the event that your cushions are severely uneven, you can purchase replacement foam from a craft store, furniture store, or home improvement store to fix your sagging sofa. With the fabric removed from the cushion, measure the areas that need to be replaced, and cut pieces of foam to fit them. When you’re done, push the foam into the holes and place the fabric casing back over the cushion. If all of the foam is severely deteriorated, measure the size of the fabric casing, including width, depth, and height, and cut pieces of foam to these measurements. Discard of the old foam, and use the new pieces to fill out the fabric.
