Do it Yourself Foam Cushion Replacement

Measure the length, width and depth of the cushion you need to replace. Subtract a 1/2 inch from each dimension to accommodate the foam batting and fabric that you will use to create the new cushion. Purchase a piece of 4-by-6-inch thick high-density foam in those dimensions. Find high-density foam at an upholstery supply store or a sewing store. The store will cut the foam to size for you.

Cut two pieces of extra-loft foam batting to the exact size of the top and bottom of the high-density foam piece. Cut one piece of extra-loft batting that equals the length of the perimeter of the foam piece. This piece of foam batting should be the same width as the depth of the foam piece.

Cover the top and bottom of the foam with a piece of foam batting cut to the same size as the length and width of the foam piece. Apply a light coat of spray adhesive to the top of the foam piece. Put a piece of foam batting on top of the spray adhesive and press down to make sure the batting adheres to the foam piece. Repeat for the bottom of the cushion. Arrange the long piece of batting along the sides of the foam piece and secure it in place with the spray adhesive.

Measure and cut out two pieces of fabric, each 1 1/2 inches longer and 1 1/2 inches wider than the foam piece with the batting attached. The extra fabric will be used for the seam allowance (the 5/8-inch space between the edge of the fabric and the seam when you sew the cushion cover, or the amount of fabric you allow for the seam) and to ensure that you can get the foam piece into the cushion cover.

Measure the perimeter of the top of the cushion. This is the length of fabric you will need to cover the sides of the cushion. Cut a piece of fabric that equals the length of the foam piece plus 1 1/4 inches for the seam allowance. The width of the fabric should be the same as the depth of the cushion plus 1 1/4 inches.

Match up the two ends of the long piece of fabric with the right sides together. The right side of the fabric is the side you will see when the cushion cover is on the cushion. Right sides together means the right sides of the fabric should face each other. Use a sewing machine to sew the two short ends of the long piece of fabric together. Pin the two ends together using straight pins placed perpendicular to the edges of the fabric about 2 inches from each other. Sew the seam 5/8-inch from the edges of the short sides of the fabric and parallel to those edges. Remove each straight pin as you sewing machine foot comes to it to avoid breaking the sewing machine needle. Each seam you sew for this project will be pinned in this manner and sewn 5/8-inch from the edge of the two pieces of fabric you are sewing together.

Pin the long piece of fabric around the edge of the top of the cushion cover. The right sides of the cushion cover top and the long piece of fabric should be facing each other. The edges of the two pieces of fabric should be aligned exactly.

Sew the long piece of fabric to the top of the cushion cover using a sewing machine and thread that matches the fabric. When you have finished sewing, cut some of the fabric away from the corners of the cushion cover so the cover will fit properly. Sew the other side of the long piece of fabric to the bottom of the cushion cover in the same way. Leave an opening on one long side of the cushion cover. This is where you will insert the foam cushion. Cut away the come fabric at the corners.

Turn the cover inside out so you can see the right side of the cushion cover. Insert the foam cushion covered with batting into the cover. Hand sew the opening together using a needle and thread.