How to Replace Sagging Sofa Seat Cushions

A sagging sofa seat can come from compressed foam, stretched covers, damaged springs or a weak seat platform. Check the whole seat before assuming the foam is the only cause.

Inspect the sofa

Remove the cushions and look for broken webbing, bowed boards, damaged springs or loose fixings. Replacement foam cannot correct a structural problem underneath it.

Examine the cover

Check seams, zips and fabric tension. A stretched cover may still appear loose around new foam. If the cover is washable, follow its care label and make sure it is completely dry before measuring or refilling.

Measure the existing cushion

Measure the old foam on a flat surface at several points, then compare it with the empty cover and the furniture space. Record length, width and depth in one unit. Note rounded edges, tapers or cut-outs.

Choose a suitable foam option

Compare the product's firmness, density, thickness and intended application. Everyday sofa seats generally need a supportive grade made for repeated compression. Memory foam and recon foam have different constructions and feel, so use the product specification rather than the name alone.

Fit and assess carefully

Insert the replacement without forcing the zip or seams. Allow the cushion to settle, then check that it sits evenly and does not obstruct moving furniture parts. Keep the order specification in case another matching cushion is needed later.

Browse replacement sofa cushions or get a custom foam estimate.