If the foam in your couch cushions is damaged or flat, it is often more economical to replace it than to buy a new couch. To replace couch foam, you must first measure the old foam. You can then purchase foam blocks to fit into your cushion covers. In some cases, you will need to cut the foam to fit into your cushion covers.
To replace couch foam, you will need to know the dimensions of the foam. This can usually be discovered by measuring the old foam insert, which can usually be removed by opening the zipper on the back of the couch cushion cover. If this is too flattened or otherwise damaged, you can measure the couch cushion covers. It is also recommended that you add at least 1 inch (2.54 cm) to each measurement.
It will usually help if you sketch the original shape of your old couch foam. This drawing can then be labeled with the measurements. You will need to measure the length and width of the foam, along with the height. If the cushion has an odd shape, like an L shape, don't forget to measure that part of the cushion as well.
After you get these measurements, you will need to purchase the couch foam. Most fabric and craft stores will carry this type of foam. If you can not find it locally, you will usually be able to order it online.
Depending on the shape and dimensions of your couch cushions, you may be able to purchase couch foam that requires no measuring or cutting. Pre-cut foam inserts can usually be specially ordered online. Usually, all you would need to do is enter the dimensions of your cushions. If you are unable to do this or it is to expensive, you can also purchase large foam blocks and cut them yourself.
When purchasing foam blocks to replace your couch foam, choose blocks that are the same height as your couch cushion. You can then mark the foam block where you need to cut it. This can easily be done by laying the old couch foam on the new foam and tracing around it with a marker. You can then cut the foam using a serrated knife. Many experts recommend using an electric carving knife for this job.
After the new couch foam is cut, it can then be inserted into the cushion cover. If it will not fit, you may need to trim a little bit off of each side. You can also add batting around the foam too.