How to Fix Sagging Sofa Cushions

To fix sagging sofa cushions, start with the simplest option and work up. Rotate and flip the cushions, plump up any flattened fill, add new fill or a new foam insert if the old one has broken down, and place a support board underneath if the base has lost its support. Cushions usually sag because the foam compresses or the fill flattens with everyday use, so working out the cause first tells you which fix will help. Below, we explain what causes sagging, how to fix it step by step, which fixes last longest and how to stop it happening again.

Key Takeaways

• Start with the easy fixes. Rotating, flipping and plumping your cushions often brings back their shape.

• Sagging usually comes from compressed foam, flattened fill or a tired base, and each one needs a different fix.

• New fill or a new foam insert is the longer-lasting fix when the original filling has broken down.

• A support board under the cushions helps when the base is the problem, especially on older sofas.

• If you own a Koala sofa, check your warranty before changing any parts, and get in touch with us if something doesn't seem right.

What Causes Sofa Cushions to Sag

Sofa cushions sag when the foam inside compresses, the fibre or feather fill flattens and clumps, or the base under the cushions loses its support. It's often a mix of these, so it helps to find the cause before you start.

• Foam compression. Foam slowly loses its bounce with use, and lower-density foam softens sooner. According to furniture industry veteran Jeff Frank, 25 kg/m³ foam is the standard density in most furniture stores and lasts around 3 to 5 years, while 35 kg/m³ foam can last 10 years or more.

• Flattened fill. Fibre and feather fill can bunch up in one spot when you always sit in the same place.

• A tired base. Springs or webbing under the seat can stretch over time, so the cushions have less support underneath.

• Uneven use. Sitting in the same seat every day puts all the wear on one cushion.

To find the cause, lift the cushions and check the base for loose or stretched springs. Then press firmly into the middle of the sagging cushion. If it feels empty or lumpy, the fill has flattened. If it feels solid but low, the foam has compressed. If the whole seat sits lower than the rest of the sofa, the base may be the problem.

How to Fix Sagging Sofa Cushions

Work through these four fixes in order, starting with the simplest. Most sagging improves with the first two steps, so you may not need to go further.

Step 1, Rotate & Flip the Cushions

Swap your cushions between seats and flip them over so the wear spreads evenly. This works well when a cushion has only started to sag and the foam is still in good shape. We recommend regularly rotating your cushions, changing their positions and plumping them up, which keeps them looking full and helps prevent a worn "favourite spot".

It takes a few minutes and costs nothing, so it's the best place to start.

Step 2, Beat Out Compacted Filling

Fibre and feather fill can flatten and bunch up with daily sitting. Take each cushion off the sofa, then plump and pat it firmly on all sides to spread the fill back out. This works best on fibre-filled and feather-filled cushions and does less for solid foam.

You may need to repeat this every so often, as the fill will settle again with use.

Step 3, Add Extra Stuffing or a New Foam Insert

If rotating and plumping don't help, the fill or foam has probably broken down. On most sofas with zip-off covers, you can unzip the cover, add polyester fibre fill or fit a new foam insert cut to size, then zip it back up. Choose a higher-density foam if you want the new insert to last. Upholstery and foam suppliers can usually cut foam to your measurements.

If you own a Koala sofa, please don't open or replace the inner cushion parts yourself. Changing components without our advice can void your warranty, so contact our team first.

Step 4, Secure Attached Cushions With a Support Board

If the sag comes from the base rather than the cushions, a support board can help. Measure the seat area and cut a piece of plywood to fit, then lay it flat on the frame under the cushions so it supports them evenly without overhanging. This is a simple fix for older sofas where the springs or webbing have stretched.

If the springs themselves are broken, a professional upholsterer can repair or replace them.

Quick Fix vs Long-Term Fix

Some fixes are quick and free but need repeating, while others take more effort and last longer. Here's how they compare.

Start with the free fixes and move on to new fill, new foam or a support board if the sag keeps coming back. If none of these help, or the frame itself is damaged, it may be time for a new sofa.

How to Prevent Sofa Cushions from Sagging Again

A few simple habits stop cushions from sagging again.

• Rotate and flip your cushions regularly so every seat gets used.

• Plump up the cushions often, especially fibre and feather ones.

• Try not to sit in the same spot every day.

• Vacuum under and between the cushions to remove crumbs and grit.

• Avoid putting heavy weight on one spot, such as standing or kneeling on the seat.

• Choose higher-density foam if you ever replace an insert.

For more everyday care tips, read our guide on how to clean a sofa. To compare the materials used in sofa upholstery, see our sofa fabric guide.

Sofas Built to Hold Their Shape

If your current sofa is past the point of fixing, our sofas are designed to stay comfortable for years. Our Tamarama Modular Sofa, for example, uses heavy-duty S-spring suspension that spreads weight evenly to help prevent sagging. Every one of our sofas comes with a 5-year warranty that covers manufacturing and material defects, plus our 120-day trial.

• • Browse our full range of sofas and couches across every size and style.

  • Give an existing Koala sofa a fresh look with our washable sofa covers.

  • Add new cushions and throws for extra comfort and colour.