10 Common Reasons Your Sofa Sags — and How to Fix Each One

A sagging sofa is usually caused by worn-out foam, broken springs, or weak frame support—but you can fix it at home with new cushion inserts, plywood reinforcements, or simple DIY repairs.

You sit down to relax—and suddenly sink halfway to the floor. Sound familiar? A sagging sofa isn’t just uncomfortable—it can make your whole living room feel tired and worn out. Whether it’s from years of cozy movie nights, a poor-quality frame, or just cheap cushion stuffing, the problem is more common than you might think.

But here’s the good news: you don’t need to toss your couch or spend a fortune on a replacement. After years of testing different fixes (and rescuing more than one sad-looking sofa), I’ve found easy, affordable ways to bring life back to your seating. From quick foam swaps to frame reinforcements you can do with a screwdriver, I’ll walk you through every practical fix—step by step.

Let’s dive into the 10 most common reasons your sofa is sagging and exactly how to fix each one—DIY-style.

1. Worn-Out Cushion Foam

When your sofa starts to feel flat or bouncy in all the wrong places, old cushion foam is often the culprit. Foam breaks down over time, especially in high-use areas like the center seat or your favorite corner. This makes the couch feel saggy and look tired.

How to Fix It

You don’t need a full reupholstery to fix this. Just replace the old foam with high-density foam. It’s firm, long-lasting, and gives your cushions their shape back. You can find cushion foam at stores like Joann or Amazon.

If you want a softer feel, try memory foam or a mix of foam and batting. Cut the foam to size using a bread knife or electric carving knife.

Pro Tip: Add a layer of polyester batting for a smooth, full look. It also helps the cushion covers fit better.

2. Broken or Weak Sofa Springs

Sofa springs do the heavy lifting when it comes to support. If they break, bend, or stretch out, your couch will sag no matter how good the cushions are. You might even hear creaks or feel sudden dips when you sit down.

How to Fix It

Start by removing the cushions and checking under the seat. Look for sinuous (S-shaped) springs or coil springs. If they’re loose, try reattaching them with clips or zip ties. If they’re broken, you can replace them with a spring repair kit from a hardware store or upholstery supplier.

Here’s a quick comparison to help you choose:

Spring Type	Signs of Damage	Repair Method	Where to Buy
Sinuous Springs	Sagging, uneven seat	Re-clip or replace	Sailrite
Coil Springs	Noisy or lopsided	Retie or replace	DIY Upholstery Supply
Webbing Straps	Soft seat feel	Replace with stretch webbing	The Foam Factory

Safety Note: Always wear gloves when working with springs—they can snap back and pinch.

3. Stretched or Torn Webbing

If your sofa doesn’t have springs, it likely uses webbing for support. Webbing is made of elastic or jute straps and sits under the cushions. Over time, it can stretch out or tear, leaving your seat with no support.

How to Fix It

Flip your sofa and unscrew the bottom cover. You’ll see a grid of woven straps. If they look loose or broken, it’s time to replace them. Use a staple gun and webbing stretcher to install new webbing tightly across the seat frame.

You can find quality webbing kits at DIY Upholstery Supply or Home Depot.

DIY Tip: Mark where each strap was before removing it so you can keep the original pattern. This helps keep your seat firm and even.

4. Frame Damage or Weak Structure

When your sofa feels wobbly or tilts to one side, a weak or damaged frame is often the cause. Frames made with softwood or particleboard can crack or warp over time, especially under daily use.

How to Fix It

First, remove the bottom dust cover and inspect the wood frame. Look for cracked beams, loose joints, or splintered wood. If the damage is minor, you can reinforce it with steel brackets or corner braces. For larger cracks, use wood glue and clamps to hold the frame while it dries.

For DIYers, check out guides from trusted sources like Family Handyman on furniture repair basics.

If the entire frame is weak or sagging in multiple places, it might be more cost-effective to replace the couch—especially if it’s made from particleboard, which doesn’t hold screws well after damage.

Pro Tip: Add a cut-to-size plywood sheet under the cushions for extra support. This simple trick can help extend the life of a sagging frame.

5. Loose or Broken Joints

Joints are where the parts of your sofa frame connect. When they loosen, your couch may creak, shift, or wobble. This usually happens with older sofas or ones moved around often.

How to Fix It

Flip the sofa and check every joint. If a joint wiggles or creaks, it likely needs tightening or glue. Use wood glue for separation and reinforce with screws or flat brackets for extra hold.

Here’s a quick repair guide:

Problem Type	Repair Tip	Tools Needed
Loose joints	Re-glue and clamp overnight	Wood glue, clamps
Separated corners	Add corner braces	Corner brackets, screwdriver
Squeaky movement	Tighten screws or add wood filler	Drill, filler, sanding block

For more help, HGTV shares helpful ways to fix creaky or wobbly furniture.

Safety Note: Make sure to let any glue cure for 24 hours before using the couch again.

6. Inferior Manufacturing or Materials

Sometimes, sagging isn’t your fault at all. If your sofa started to sink within a year or two, the cause might be poor-quality materials or rushed construction.

Cheap frames, low-grade foam, or weak springs can all lead to sagging—even with light use. Mass-produced sofas from big-box stores sometimes cut corners to keep costs low.

How to Fix It

Check your warranty first. Brands like Ashley Furniture and IKEA often cover structural issues for several years.

If there’s no warranty, you can reinforce weak spots with plywood, upgrade the foam, or even rebuild part of the frame. But if multiple parts are failing, replacing the sofa may be the better long-term option.

Pro Tip: When buying a new couch, look for hardwood frames, sinuous springs, and CertiPUR-US certified foam for longer life. The Spruce has a helpful guide on what to look for in a quality sofa.

7. Cushion Covers That Are Too Loose

Loose cushion covers might not seem like a big deal, but they can make your sofa look saggy even if the foam and frame are fine. Over time, fabric stretches and zippers wear out, making the cushions look baggy and feel less firm.

How to Fix It

First, check if the cushion insert still fits the cover snugly. If not, you can add polyester fiberfill or wrap the cushion in batting for a fuller shape. This adds volume and helps the cover sit more smoothly. You can find both at stores like Joann or Walmart.

If the cover is stretched out, consider shrinking it slightly in the wash—but only if it’s made from cotton or linen. Always check the tag first. If shrinking isn’t an option, adding Velcro strips inside the cover can help tighten it up.

DIY Tip: Wrap your cushion insert in a layer of quilt batting, secure it with spray adhesive or tape, and then slip it back in the cover. It’s an instant firmness upgrade.

8. Improper Sofa Usage (Jumping, Standing, or Overloading)

Let’s be honest—sofas take a beating. Kids jumping, adults standing, or even just too many people piling on can wear it down fast. This kind of strain stretches springs, flattens foam, and can even crack the frame.

How to Prevent and Fix Damage

Set some basic sofa rules—no jumping or standing on the cushions. If it’s already sagging from rough use, inspect the springs, webbing, and frame for signs of damage.

Add support by placing a firm board (like plywood) under the cushions. It’s an easy way to reduce sag and protect against further wear. You can also rotate cushions regularly to prevent uneven sinking.

For more smart home tips, check out this Better Homes & Gardens article on how to care for your sofa the right way.

Pro Tip: If your couch has a removable chaise or sectional piece, rotate its position every few months. This helps even out wear on the frame and foam.

9. Age and General Wear Over Time

Even the best sofa won’t last forever. Foam compresses, fabric fades, and frames weaken with age. If your couch is over 8–10 years old, sagging is usually just a natural sign of wear.

How to Extend Sofa Life

Start by giving it a full check-up—foam, springs, frame, and webbing. Replace whatever parts you can, and reinforce where needed. Add a plywood board or cushion insert upgrade to get a few more years out of it.

If you’re considering an upgrade, look for sofas with solid wood frames, sinuous spring systems, and replaceable cushions. These last longer and are easier to maintain. Consumer Reports offers a great guide on what to look for in a quality, long-lasting sofa.

DIY Tip: Even an old sofa can get a second life with new slipcovers, cushion foam, and better support underneath. Add stylish throws and pillows, and no one will guess it’s pushing a decade.

10. Heavy or Unsuitable Upholstery Fabric

Some fabrics are just too heavy for lightweight frames. Thick materials like velvet or chenille look beautiful but can pull on the frame and cushions if the sofa isn’t built to handle the weight.

How to Fix It

If your fabric feels like it’s dragging the sofa down, consider removing the covers and checking how they attach. Loose-fitting fabric adds weight and makes sagging worse.

You can swap out heavy cushion covers for lighter fabrics like cotton or polyester blends. These are easier on the frame and still look stylish. The Spruce offers a good guide on choosing upholstery that balances weight and durability.

Pro Tip: If you love the look of heavy fabric, balance it out with firmer foam and solid internal support. This keeps everything lifted and looking sharp.

Quick DIY Fixes for Sagging Sofas

Sometimes, a full repair isn’t in the cards. But that doesn’t mean you have to live with a sad-looking sofa. These easy fixes can give your couch a fresh feel in under 30 minutes.

Instant Fixes to Try

DIY Fix	Best For	What You’ll Need
Add a plywood board	Soft or sinking seats	½-inch plywood sheet, sanded edges
Cushion filler boost	Flat cushions	Polyester fiberfill or quilt batting
Flip and rotate cushions	Uneven wear	None—just a good habit
Sofa support insert	Overall sag	Foldable support board from Amazon
New foam inserts	Long-term firmness	High-density foam, electric knife to cut

Quick Win Tip: Combine two or three of these fixes for a big difference without spending much. It’s the easiest way to extend your sofa’s life while saving for a long-term solution.

FAQ: Sofa Sagging Fixes

How do I know if my sofa frame is broken?
Check under the dust cover for any cracked wood, loose joints, or bent springs. If your couch tilts or sinks unevenly, the frame is likely damaged.

Can I fix a sagging couch without buying new cushions?
Yes! Use plywood under the cushions or stuff the covers with fiberfill to restore firmness. These are cheap, fast fixes that make a big difference.

How long should a sofa last before it starts sagging?
Most well-made sofas last 7–15 years. If sagging happens earlier, it could be due to poor materials or heavy use.

Is it worth fixing an old couch?
If the frame is solid, yes. A little DIY care—like replacing foam or tightening joints—can make an old sofa feel new again.

Conclusion: Say Goodbye to Sofa Sag

A sagging sofa doesn’t mean you have to toss it out. With a few smart tricks—like adding plywood, upgrading the foam, or reinforcing the frame—you can bring back comfort and style in no time. Whether it’s a quick fix or a weekend project, these solutions are easy, affordable, and totally doable.

And hey, if you’ve revived your couch with one of these tips, why not show it off? Snap a before-and-after pic and tag your post—you might just inspire someone else to save their sofa too.