Flat Sofa Cushions? How to Fix Them Without Buying a New Sofa

Quick answer: Flat sofa cushions are almost always worn-out foam, not a worn-out sofa. Do a press test. If the covers still look good, order new foam cut to the size of each cover. If the fabric is tired too, order complete cushions. Use HD36-R or Lux-R foam for seats, and keep Super Soft foam for back cushions only.

Canadians spend a lot of time on the sofa between November and April. Hockey nights, long weekends at the cottage, snow days with the kids home from school: the seat cushions take every one of them. Eventually the middle seat sags, the back cushions look deflated and the whole sofa seems tired, even though the frame is perfectly solid.

Before you start shopping for a new sofa, check the cushions. In most cases you can bring the sofa back for a fraction of the effort, and you keep the frame you already like.

Why sofa cushions go flat

Foam is a network of tiny cells that squash when you sit and spring back when you stand. Over years of daily use, those cells break down and stop recovering fully. Lower-grade foam, common in budget sofas, gives up sooner. Back cushions filled with loose fibre tend to clump and go lumpy rather than flat.

Where the sofa sits makes a difference too. A sofa pushed up against a baseboard heater or a forced-air vent, or one that catches strong afternoon sun through a south-facing window, tends to wear faster than one in a cooler spot. It is worth keeping a little gap between the sofa and the heat source.

Cottage sofas have their own story. A sofa that sits in a cold, closed-up cottage all winter and then gets heavy use all summer often feels firm and fine in May and flat by August. The foam is simply near the end of its life.

Foam problem or cover problem? A two-minute test

Seat cushions

1. Take a seat cushion off the sofa and lay it on the floor.
2. Press the centre down firmly with both hands, then let go.
3. Good foam springs straight back. Foam that comes back slowly, stays dented or feels firm at first and then collapses under steady pressure needs replacing.

Back cushions

Fold the cushion in half and let go. A healthy back cushion opens up straight away. One that stays half folded, or feels lumpy when you run your hand over it, needs new filling.

When the foam passes but the cushion still looks flat

Covers stretch over the years. If the foam passes the press test but the cushion still looks wrinkled and baggy, the cover is the problem. Lay the cover flat, zip it closed and measure it. If it is clearly bigger than the foam, new covers will tighten everything up again.

Your three options

1. New foam only

If the covers are in good shape, this is the simplest fix. Unzip each cover, take out the old foam and order replacement sofa foam cut to size. Browse the full custom foam range if you need other shapes.

2. New covers only

If the foam springs back but the fabric is faded, stained or stretched, order new cushion covers made to the size of your foam. This is also the easiest way to change the whole look of a room without changing the sofa.

3. Complete new cushions

When the foam and fabric are both worn out, a complete cushion is the cleanest answer. You get new foam and a new cover made together, so the fit is tight. See replacement sofa and couch cushions for shapes and fabrics.

Every one of our builders lets you choose cover only, foam only or complete cushion, so you only replace what has actually worn out.

How to measure, in inches

We make cushions in inches, and getting the numbers right is the most important part of the job. Use a metal tape and round to the nearest quarter inch.

• For new foam: measure the cover, seam to seam, for width, depth and thickness. Order foam to that size so it fills the cover fully.
• For new covers: measure the foam, edge to edge.
• For complete cushions: measure the sofa frame where the cushion sits, not the old cushion. Flattened foam gives you the wrong thickness.
• Measure every cushion. End seats on many sofas are a different shape from the middle seat, especially where the arms curve.
• Note the corners. Many sofa seats have rounded front corners or a T-shape around the arms. Shapes like these are best sent as a template.

Our guide to measuring for custom cushions in inches has diagrams for every common shape. Every cushion is cut within ±0.5″ of the size you order, and if we miss that, we remake it free.

Which foam to choose

• HD36-R (High Density): a medium feel and our everyday choice for sofa seats. Supportive without feeling hard. Warrantied for 7 years.
• Lux-R (Luxury): a firmer feel for people who like to sit up rather than sink in, and for seats that get very heavy use. Warrantied for 7 years.
• Super Soft: a relaxed, sink-in feel for back cushions only. It is too soft for seats and will flatten quickly there. Warrantied for 3 years.
• Dryfast: an open-cell foam that drains water. It is meant for outdoor cushions and for screened porches or boathouses where cushions might get wet. Warrantied for 5 years.

All our foam is CertiPUR-US certified. If you are unsure about feel or thickness, our cushion thickness and foam guide compares them side by side.

Choosing fabric if you are replacing covers

New covers are a chance to rethink the sofa. Velvet adds warmth to a living room through a long winter, Warwick upholstery fabrics offer plenty of textures and patterns, and Sunbrella is a smart choice for cottage sofas, sunrooms and family rooms where spills, pets and sun are part of life. We also make faux leather and Ultraleather cushions. With more than 5,000 colours across our fabrics, ordering swatches first is a good idea. They are $7 each, and the cost is credited back as a one-time code on your order.

Make new cushions last longer

• Rotate and flip seat cushions every few months so one spot does not take all the wear.
• Keep the sofa a little away from heaters and vents.
• Plump back cushions regularly.
• At the cottage, store cushions somewhere dry over the winter rather than leaving them in a damp, closed-up room.

Ordering to Canada

Standard shapes are made in 2–3 weeks, and template or custom shapes take 5–6 weeks. Canadian orders ship with duties and GST/HST already paid, so there is nothing more to pay on delivery. Read more in our guide to ordering custom cushions to Canada. If you have a bench or window seat that needs the same treatment, see our guide to window seat and bench cushions.

Frequently asked questions

Can I replace just the foam in my sofa cushions?

Yes. If the covers are in good shape, measure each cover seam to seam and order foam cut to that size. We cut foam only, with no minimum order.

What is the best foam for sofa seat cushions?

HD36-R gives a medium, supportive seat and suits most sofas. Choose Lux-R if you prefer a firmer seat. Super Soft is for back cushions only.

Should I measure the old cushion or the sofa?

For new foam, measure the cover. For complete new cushions, measure the sofa frame, because old flattened foam will give you the wrong thickness.

Do I pay duty or GST/HST when my order arrives in Canada?

No. We ship Canadian orders duties paid and cover the import duty and GST/HST, so there is nothing to pay on delivery.