How to Fix a Sagging Couch

White Modern Couch

CreativaStudio / Getty Images

If anything good can be said of a sagging couch, it’s that you really like it, and those dips are signs of actual usage.

If you’re not ready to replace your valued piece of furniture, learn how to fix its sags by yourself. With a few adjustments, you could have a like-new couch that will provide you with several more years of comfort.

Why Your Couch Sags

There are several places and reasons for a sagging couch. The most common are outlined below.

Cushions Are Sagging

Removing the cushions from the couch is important because it narrows down the cause of the sagging. Is the sag in the cushions or in the couch frame?

Flattened cushions can possibly be revived using the same materials by turning them around. But the most effective fix is to rebuild the cushions with new foam and with polyester or Dacron wrap around the foam.

Springs Are Loose

If the cushions are in good condition, the sagging could be traced to the serpentine springs within the couch frame. Often, the springs have come loose and need to be reattached to their clips, then secured to prevent them from loosening again.

Serpentine springs, sometimes called zig-zag springs, are the long metal wires with multiple S-shapes bent into them. Located inside the couch’s frame, serpentine springs run from front to back and are critical to providing support.

Springs Are Broken Off

Serpentine springs are made of strong metal and sometimes they do break. But more often they will break off of their attachments to the wooden couch frame. Springs can be reattached and held together with twine or wire. Serpentine springs that are still attached but which have stretched out can be replaced entirely.

How to Fix Your Sagging Couch

For couch repairs, you will need a staple gun, utility knife, scissors, flat-head screwdriver, pliers, and a drill and bits.

You can inexpensively purchase multi-packs of couch repair materials, including serpentine springs, matching attachment clips, and paper-wrapped wire or twine.

Because the bottom dust cloth will usually be torn away, purchase new upholstery dust cloth fabric, as well.

How to Access the Inside of Your Couch

  1. With assistance, turn the couch upside-down.
  2. Remove the couch legs, by unscrewing them off counter-clockwise by hand or with the screwdriver or drill.
  3. Remove the black dust cover by carefully cutting it away. For a cleaner removal, pry away the staples that hold the dust cover to the couch’s wooden frame.

Steps to Reattaching or Replacing Couch Springs

  1. After accessing the bottom of the couch, find the detached couch springs.
  2. For couch springs that have become detached from the clips, reattach the springs to the clips. It may be necessary to bend the ends of the springs back into a hook shape so they hold onto the clips again.
  3. For broken couch springs, discard the existing springs. Assess the strength of the clips by gently tugging at them with the pliers. Clips that are loose should be replaced with new clips. 
  4. Add the new couch springs to the clips.
  5. Run the wire or twine perpendicular to the springs. Start by stapling the end of the line on the couch’s frame in a Z-shape, with staples at each part of the Z. Without this three-part shape, the line will pull through the staples.
  6. Loop the line through each of the serpentine wires as it travels to the other side of the couch frame. The line should be tight from wire to wire, but not so tight as to pull the wires together.
  7. End the line at the other side of the couch frame, stapling it in a Z-shape.
  8. Staple the new upholstery dust cloth fabric to the bottom of the couch, cutting away excess with the scissors.

Steps to Fixing or Replacing the Couch Cushions

Since the back side of the cushion receives less wear, in some cases, you can reverse the position of the foam inside the seat cushions, from front to back. By bringing the back to the front, it can create a more even and fluffed-up appearance. Otherwise, replace the foam and the wrap within the cushions:

  1. Unzip the couch seat cushion cover.
  2. Pull out the existing foam by turning the cushion cover inside-out.
  3. Mark the back of the new cushion foam with an indelible marker so you remember the position of the foam within the cover.
  4. Wrap the couch foam once over with the Dacron or polyester padding. The back of the cushion is not wrapped, only the front side.
  5. With assistance from a partner, slide the cushion cover over the foam. Make sure that the wrapped side of the foam is at the front.
  6. Zip the couch cushion shut again and place it on the couch.