The short answer: first find what is sagging. If the cushions are flat, flip and rotate them, add batting, or replace the foam inserts. If the seat sinks even with the cushions off, the springs or webbing under them need support: a plywood board under the cushions is the quick fix, and spring clips or new webbing are the lasting one. If the frame is cracked, a repair shop, or a new sofa, is the answer.
1. Find the cause
| Check | What it means |
|---|---|
| The sag moves when you swap two cushions | The cushions have lost their shape. |
| The seat deck dips with the cushions removed | The springs or webbing have stretched or come loose. |
| The sofa rocks, creaks or one side is lower | A leg is loose or the frame is damaged. |
2. How to fix saggy couch cushions
- Flip, rotate and plump. Swap cushions between seats and turn them over every few weeks so they wear evenly; plump fiber and feather fills.
- Add batting. Wrap the foam core in a layer or two of polyester batting to restore loft. It is cheap and quick.
- Restuff fiber cushions. If the cover has a zipper, add new polyester fiberfill where it has thinned.
- Replace the foam. For foam cushions that stay flat, order new high-density foam cut to size; about 1.8-2.5 lb/ft³ density lasts well. Our cushion firmness guide explains density and firmness.
3. How to fix a sagging seat (springs and webbing)
- Support board: cut a piece of 1/2″ to 3/4″ plywood to fit under the seat cushions, or buy a ready-made couch support. It is the fastest fix and needs no tools.
- Sinuous (zig-zag) springs: reattach loose clips, or add spring clips or connectors to pull stretched springs back into line. Turn the sofa over and remove the dust cover to reach them.
- Webbing: stretched elastic or jute webbing can be re-tensioned or replaced with new webbing stapled to the frame.
4. Check the frame and legs
Tighten loose legs first; it often cures a lean. Loose joints can sometimes be re-glued and screwed, but a cracked rail or particleboard frame is usually a job for an upholsterer, or a sign it is time to replace the sofa. See how long a couch lasts for when repair is worth it.
How to stop couch cushions from sliding
- Lay a non-slip rug pad or shelf liner between the cushion and the seat deck.
- Add hook-and-loop (Velcro) strips to the cushion and the deck.
- Check the cushions still fit snugly; flattened cushions slide more, so restoring their shape helps.
How to stop a couch sliding on a wood floor
Put rubber furniture grippers or non-slip pads under each leg, or place the sofa’s front legs on a rug with a good rug pad. Felt pads protect the floor but make sliding worse.
Want a firmer or softer seat rather than a repair? See how to make a couch more comfortable.
How to prevent sagging
- Rotate and flip cushions regularly, and don’t always sit in the same spot.
- Avoid sitting on the arms and front edge, and don’t let children jump on the seats.
- When buying, look for high-density foam and a hardwood or multi-layer plywood frame. See how to choose a sofa.
Frequently asked questions
Why is my couch sagging in the middle?
Usually because the middle springs or webbing have stretched from use, or the center leg or support has loosened. Check under the cushions and underneath the sofa.
Is it worth fixing a sagging couch?
If the frame is solid, yes: new foam or spring support costs far less than a new sofa. If the frame is broken or made of particleboard, replacing it is usually better value.