A sagging couch is frustrating — but before you spend a penny fixing it, you need to know what's actually causing the sag. Get this wrong and you'll waste an afternoon restuffing cushions when the real problem was the base underneath (or vice versa). The good news: there's a simple 2-minute test that tells you exactly what you're dealing with.

The 2-Minute Test

Here's the single most useful thing you can do before any repair:

1. Remove all the seat cushions and set them on the floor.
2. Sit directly on the exposed base of the sofa (the webbing, springs, or deck where the cushions normally rest).
3. Notice what happens. If the base feels firm and even, your cushions are the problem. If you sink, feel a dip, or feel like you're dropping into a hammock, the base is the problem.

Then do the reverse check: put the cushions on the floor and sit on them. If they feel flat and unsupportive off the couch, the cushion foam is worn. If they feel fine on the floor but bad on the couch, it confirms the base is what's failing.

What Each Result Means

What You Feel	Likely Cause	Best First Fix
Base sags with cushions removed	Worn webbing, springs, or deck	A support board on top of the base
Cushions feel flat off the couch	Compressed or worn foam	Restuff or replace the foam
Only one seat/corner dips	Uneven wear in your favorite spot	Rotate cushions, add even base support
Creaking or shifting under load	Loose joints or cracked frame	Tighten hardware; repair frame

Why the Base Is Usually the Real Culprit

Most people blame the cushions because that's what they can see. But in the majority of sagging couches, the base support — the webbing, straps, or springs under the cushions — has lost its tension. When that happens, even brand-new cushions will sink, because they have nothing firm to rest on.

This is why so many people replace their cushions, feel a brief improvement, and then find the sag comes right back. They fixed the symptom, not the cause.

The Fix for a Sagging Base

If your test showed the base is the problem, a couch support board is the fastest and most reliable fix. It's a firm, flat panel that sits between the sagging base and your cushions, creating an even surface for them to rest on. You get your seat height and firmness back without replacing the sofa — and it installs in a couple of minutes with no tools.

Because it addresses the structural cause rather than masking it, the improvement lasts. It's a fraction of the cost of a new sofa, and it works on almost any couch with removable seat cushions.

The Fix for Worn Cushion Foam

If your test pointed to the cushions instead, you have a few options: restuff them with polyester fiberfill for lost volume, or replace the foam core entirely with high-density foam for lost firmness. If the base is solid, this alone can make the couch feel close to new.

And if both are worn — which is common on older sofas — a support board plus fresh cushion foam is the complete fix.

Shop the Couch Cushion Support Board — a firm, foldable, fabric-covered board that restores even support to a sagging sofa in about two minutes. Free shipping on all orders.