If your upholstered chair cushions or seats are looking a little worse for wear, it's probably time to replace the insert. An upholstered chair insert refers to the seat piece. In a dining chair, it means the seat. In a sofa, the inserts are the individual cushions. Whether you're replacing an insert on a sofa or a dining chair, the process is similar. If the piece you're replacing also needs new upholstery, it's usually simpler to replace the insert and the upholstery at the same time, especially if you're dealing with a dining chair.
Remove the seat from the chair. Unscrew the seat from the chair itself with a screwdriver.
Pull the staples out of the bottom of the chair with a pair of needle-nose pliers. Remove the fabric. Unwrap the batting from around the insert. Most dining room chair inserts are wood.
Measure the width of the wood insert with a measuring tape. Use the original insert and a pencil to trace a new insert out of a piece of wood of the correct width. Cut out the new insert with a saw. Place the new insert on top of the original to make sure both pieces are the same size.
Place the new insert on top of the piece of fabric with which you plan to cover the chair, if you're reupholstering the piece. Use a pair of scissors to cut the fabric around the seat. Leave approximately 3 inches extra on every side of the insert. This provides extra fabric to cover the batting later.
Take the insert off the fabric, and lay it on top of a piece of batting, top side down. Pull the batting until it fits snugly around the seat. Use a staple gun to staple it in place. Cut away the excess batting with a pair of scissors.
Place the insert on the piece of fabric. The batting side of the insert should rest against the back, nondesign side of the fabric. Pull the fabric tightly over the seat. Staple the edges of the fabric to the bottom of the seat on all four sides. Do not stretch the fabric so much that the design of the fabric stretches. You want it to fit snugly but not too tight.
Screw your seat with the new insert back onto your dining chair.
Remove the cushion from the piece of furniture. Unzip the back of the cover and pull it off the cushion. Remove the netting and the batting from the cushion.
Trace the shape of your old sofa cushion onto a new piece of 5-inch-thick foam using a pen or marker. Measure the width of the highest part of the cushion with a measuring tape to get the proper width of the cushion if the cushion is damaged or worn. Draw a corresponding cut line on the new foam.
Use an electric carving knife to cut out the new foam cushion. Place the new foam cushion against the old foam cushion to make sure they're the same size.
Wrap the new cushion in a layer of batting. Do not wrap the sides of the cushion unless the sides were wrapped in batting on the original cushion. Adding batting to the sides when none was originally present can make the cushion not fit properly.
Cover the entire cushion in netting. A thin netting, such as cheesecloth, keeps the batting on the cushion in place. Pull the sofa cushion cover back onto your new sofa insert. Zip it closed. Place the cushion on the sofa.
If the original wood dining chair insert features drill holes, you'll need to create drill holes in your new insert for the screws. Make sure when you staple the batting and fabric onto your dining chair insert that you make the corners as clean and neat as possible. Messy corners will make it difficult to put the seat back on the chair. You can reupholster your sofa cushions when you replace the insert. Simply cut the old cushion apart at the seams. Cut pieces of fabric to match the old pieces. If you've never reupholstered a cushion before, try a simple square or round cushion before moving on to more complex cushions with gathered edges.
Use standard-thickness upholstery batting to cover inserts. Do not use a thicker quilt or comforter batting. These are often too thick and can make it difficult to apply the upholstery over the insert once it's completed.