How to fix a sagging couch: Easy DIY repair tips

A sagging or sunken couch feels uncomfortable. It can leave you feeling unsupported, slouched, and sore in your back, hips, and legs. In some cases, you can even feel the frame or springs underneath. 

Most of the time, the issue comes down to one of three parts: the cushions, the frame, or the springs.

The good news is that you can repair it yourself as a DIY project, save money, and extend the life of your furniture.

Keep reading to learn how to fix a sagging couch and prevent it from happening again.

How to diagnose a sagging couch

A sagging couch is uncomfortable and a sign that something’s not right inside the furniture. Usually, the problem comes from one or more of three things: the cushions, the frame, or the springs. Each part significantly affects how your couch feels and how well it holds up over time. 

You’ll need a staple gun, flat-head screwdriver, scissors, flashlight, pliers, drill and drill bits, twine, measuring tape, serpentine springs, and attachment clips.

Checking the cushions

Over time, the foam or stuffing inside the cushion breaks down and flattens out. Remove the cushions and set them aside. Press down on each one with your hands. If a cushion feels too squishy or looks flat, it means the foam or stuffing inside has worn down. 

Swap the cushion with one from another part of the couch as a confirmatory test. If the sagging spot moves with the cushion, then the cushion is the problem.

Inspecting the frame

If the cushions seem fine, the next step is to check the couch's frame. The frame is the base structure that holds everything together, and a damaged frame can’t properly support the weight, leading to a sinking feeling when you sit. Carefully inspect the wood or metal parts that make up the structure. Look for visible cracks, broken slats, or bent metal. 

Gently press down on the area that sags. If it feels weak or moves more than other parts of the couch, it may be a broken slat or joint. In addition, listen for creaking or popping sounds when you apply pressure. These noises signify that something is loose or broken inside the frame.

Examining the springs

The springs inside the couch give it bounce and support your weight. If they’re broken, loose, or stretched out, your couch will feel saggy even if the cushions and frame are okay. Look under the sofa or unzip the bottom fabric if possible. The springs should be evenly spaced and firm. If you see any springs that are broken, missing, or hanging loosely, they’re likely the cause of the sag. Press down on the seat and feel for areas that give way too much or don’t bounce back.

How to fix a sagging couch

The best way to repair a sagging couch depends on which part is causing the issue. If it’s the cushions, you might only need to add more filling. If it’s the springs, you will need to reattach them. If it’s the frame, you will need to support or replace the part.

Fixing sagging couch cushions

Over time, people tend to sit in the same spots, which causes one side of the cushion to wear out faster. To fix, turn the cushion over or switch its position with another cushion.

If flipping them doesn’t help enough, add more stuffing. Unzip the cushion covers and place new foam inserts or polyester fiberfill inside the corners and flat areas until the cushion feels firm and even again. Don’t overstuff it, or the cushion might not fit back into the cover.

If the cushions still feel too soft, even with more filling, place a sofa topper or cushion support board under them to add extra lift. 

Repairing a couch with sagging springs

Knowing how to fix a couch with sagging springs starts with identifying whether the springs are loose, stretched, or broken. Most couches have serpentine springs running from front to back underneath the seat. If a spring is just detached from the frame, reattach it using pliers and replacement spring clips or screws. Make sure the spring is pulled tight before securing it in place, so it offers enough support. 

If the spring is stretched out or broken, you’ll need to replace it. You can find replacement springs online or at hardware stores.

Once all the springs are back in position, press down on the seat to ensure everything feels firm and even. If the springs still seem too loose, weave some twine across them in a crisscross pattern to give extra strength. This helps to spread the weight and keeps the springs from sinking again too soon.

Fixing a sagging couch frame

If you have a broken slat, measure the length and width, then cut a new piece of sturdy wood like pine or plywood to match. Use wood glue and screws to secure the new slat in place. If the wood isn’t broken but feels weak or soft, reinforce it by attaching a second board beside it.

If the issue is a sagging center support, measure and cut a 2x4 piece of wood to serve as a reinforcing beam. Attach it underneath the sagging section with wood screws. If part of the frame is loose, tighten the screws or bolts that hold the pieces together. If the hardware is missing or stripped, replace it with new screws. You can also add metal brackets or corner braces to help hold the frame together.

However, if the wood is rotted, several significant pieces are broken, or the entire frame feels unstable, it might not be worth repairing. In that case, replacing the whole frame or getting a new couch is better.

Preventing future sagging

Regular care can significantly affect how long your couch stays comfortable and supportive. It also helps you avoid having to fix couch sagging later on. Here are some easy tips to help prevent sagging in the future:

• Rotate and flip the cushions regularly to spread the wear and keep one spot from getting too soft. Try to do this every couple of weeks, especially if people usually sit in the same place.
• Fluff the cushions, as you would with pillows. This helps keep the filling evenly spread and adds more shape and firmness.
• Look under the couch every few months to ensure the springs are still attached and the frame is strong.
• If your couch is already a few years old, place a support board underneath the cushions to help keep everything firm and reduce stress on the frame and springs.
• Don’t jump or stand on the couch, as doing so can put too much pressure on the couch, damaging the frame or stretching out the springs.
• Clean your couch regularly to prevent the filling and fabric from breaking down due to dust, dirt, or moisture buildup.

Sagging couch repair

Figuring out how to fix a sinking couch might seem like a big job at first, but it’s totally doable as a DIY project with the right approach. The key to learning how to fix a couch that sags is to diagnose the problem correctly. Once you know where the problem is, the solution becomes much more straightforward.