How to firm up a leather sofa?

by Ginger

I recently purchased a used sofa. It is in good condition except you sink too far down. So, then I purchased some good foam for the cushions. But then, I just put the whole foam piece under all the cushions and THAT feels great. I have opened a cushion and I don’t think I can get this foam into the cushions. Plus, now I don’t think that’s where it needs to go. The frame needs it but then, I don’t know what to do. Any suggestions will not be more ridiculous than this picture.

q how to firm up a leather sofa
  13 answers
  • Cheryl A Cheryl A on Dec 12, 2021

    here is info to help you out with your sinking issue

  • Cheryl A Cheryl A on Dec 12, 2021

    I have also heard of cutting a board to put on top of the frame then adding padding and cushions not sure if you can do that or not - you could also call an upholstery shop and ask them for info

  • Redcatcec Redcatcec on Dec 12, 2021

    Hi Ginger,

    Here is a suggestion that will stop the sinking:

    Plywood under couch cushions

    Plywood offers a strong furniture base; thereby, preventing the cushions from sagging.

    It’s a simple DIY method so you don’t need to be professional to do it.

    Get the plywood that is about 1/4"-1/2" thick.

    Cut it into a rectangular shape based on the measurements of your couch.

    Make sure the plywood perfectly fits the length and the width of the coach sitting area.

    Place the plywood on the couch frame without the cushions. If it sticks too far past the front of the couch, cut it until it fits perfectly.

    Since the plywood will be rough on the cut edges, you will need to cover the edges so that they don’t hurt you or snag the cushions.

    You can use duct tape or get slipcovers to cover the plywood while protecting the seat from damage.

    Place the cushions back on the couch and relax since there will be no more sagging.


  • William William on Dec 12, 2021

    I would go with 1/2" to 3/4" plywood on the frame then the cushions. 1/4" is too thin and would flex. Should stiffen things up and prevent the sagging. You can also upholster the cushion you bought and place it on top of the plywood then the sofa cushions or try it without the plywood. Usually it's the springs that start to weaken and sag.

  • If the seat of the sofa is sinking, it's usually the springs/frame are worn out. A simple solution is to put a piece of plywood under the cushions.

  • Dee Dee on Dec 12, 2021

    Plywood is a great start to firm up the cushions. But for the foam you are need to cut it to the shape of the cushion. Stuff it in and then either zip it closed or sew it closed.

  • You can get some plywood and slip it under the cushions for support or I know you can also buy a gizmo that does the same thing.

  • Simple Nature Decor Simple Nature Decor on Dec 13, 2021

    you can cover the foam with the same color leather.

  • Ginger Ginger on Dec 13, 2021

    More from ginger about leather sofa and foam

    • Ginger Ginger on Dec 19, 2021

      What about keeping the foam, which makes the sofa firm, and then using a hot foam cutter and cut the front into a sloping angle? Suggestions?

  • Mogie Mogie on Dec 13, 2021

    DIY Plywood or Particle Board Couch Cushion Supports

    Another option is to add additional support underneath your couch cushions. While there are products that achieve this (see below), you can also choose to create your own solution if you have a few tools available. You will need:

    • 1/2″ particle board or plywood
    • Measuring Tape
    • A saw (optional – you could get your wood cut to size in-store)

    To create your support, you simply need to remove your existing cushions and measure the size of plywood you need. Make sure the wood won’t stick out under the cushions, as this will be comfortable when sitting on the furniture.

    Replace Your Couch Springs

    If your couch springs have broken they won’t provide your cushions with enough support. This can be mitigated by adding additional supports in, but in some cases you’ll need to replace the springs. If you are confident in your DIY skills, there are repair kits available on Amazon.

    If yo

  • Flipturn Flipturn on Dec 14, 2021

    Trying to cover the new piece of foam with leather would not be cost effective, even if you could find enough leather to match the old cushions.

    Besides, sewing leather requires a certain amount of experience, as well as special presser feet and needles for your sewing machine.

    Covering it with fabric would not need as much sewing skill, and it would be easier to find fabric the same color as the cushions.

  • Kathy Gunter Law Kathy Gunter Law on Dec 14, 2021

    Cut a piece of plywood to fit underneath the cushions. There is also a product that is slats designed for this problem.

  • You can utilize plywood for this one. It will help in firming up cushions, since if the seat is sinking usually the frame is worn out. Another thing for the foam you need to cut it into the shape of the cushion.