Materials? To make a super firm seat cushion for my soft cushion chair

by Sharon
I bought a soft cushion chair, and the seat cushion is worn down inside and soft. I want to replace it with a firm cushion, so I don't sink when I sit in the chair. The existing cushion has a zipper and a foam piece inside. The foam insert is almost falling apart, and not sure if I can buy a very firm piece to replace it with. I was considering making a duplicate of the cushion to put under the existing cushion, but I don't have the matching fabric.
Can anyone give me some ideas? Please?
Thank you.
My new (old) blue chair!
  9 answers
  • Janice Janice on May 05, 2018

    Foam can be purchased at JoAnn's or another hobby/craft/fabric store. It comes in various degrees of firmness and thickness. Since you are limited to the depth because of your existing cushion, you might want to get the most firm foam you can. You might be able to get an even better piece from an upholstery shop as they likely have a better selection and commercial grade foam. Hope this helps!

    • Sharon Sharon on May 06, 2018

      Hi Janice,

      Thanks for your input, will look into the upholstery shop.

  • Jcraw Jcraw on May 05, 2018

    Since it does unzip, buy faux-down queen pillow and use that filling under the present foam.

    Make a pattern of the cushion out of old sheet, whatever. You can adjust it in its case. Upholstery shop foam over $150 where we checked.

    • Sharon Sharon on May 06, 2018

      Hi, Are you saying to leave the pillow as is, and just cover it? Or take out the filling? Please advise.

  • Ken Ken on May 05, 2018

    There are places that sell custom cut replacement foam cushions. Google search for one in your area.

    • Sharon Sharon on May 06, 2018

      Hi Ken,

      Thanks for your easy idea!

      Going to look at the upholstery shop this week.


  • Liz Liz on May 05, 2018

    And, if you get two thinner pieces of foam lay them perpendicular and glue together, don't forget the dacron wrap for the foam. You can also glue a rigid piece of "wood" in between or on the bottom of the cushion to provide additional stiffness. Check out the webbing on the bottom of the chair and repair as well.

  • Dee Dee on May 05, 2018

    Cheapest, easiest and quickest is place a board between the cushion and the seat of the chair. It doesn't have to be exact size or shape of the cushion as long it is under the largest part of the cushion where you sit. Make at least an inch or so smaller than the cushion so the board won't show in the front. The board should be at least 3/8" to1/2" thick.

  • Jcraw Jcraw on May 06, 2018

    No, make your cushion-shaped cover with a big enough opening that you can stuff it.

    Take some stuffing out of the bought pillow. Put it in your new cover, adjusting it so it lays kind of flat so you can get it into the chair cushion. Put your new cover inside your chair cushion, and then continue to fill it as much as you think it needs, and adjusting so it lays evenly.

    Close that new pillow cushion with lots of staples, safety pins or Velcro so the stuffing can’t sneak out but you can get back in if it needs more stuffing. Or less.

    Zip up the chair cushion.

    Save any excess for adjustments.

    I’d work in an area that’s easy to sweep up, because stuff will fall on the floor.

  • Ann Ann on May 09, 2018

    If the foam is falling apart you might do better to throw it out. Wait a week or so and Joann’s will have a 50% coupon to buy the firmest, thickest foam you can afford,. Because you don’t want to feel like you’re sitting be on a box, you must wrap it in batting. Joann’s can tell you how. You can also add a noard if you need to, but a thin foam won’t last you very long. Good luck!

  • 17335038 17335038 on Aug 10, 2018

    The two keys to purchasing replacement foam for any furniture are

    (1) Thickness, and (2) Density.

    Often these terms are mixed up, but they are not the same.

    (1) Thickness is the # of inches high that the piece is

    (2) Density correspondes to how firm or how soft the foam is. A more dense piece of the sam thickness will feel firmer to the touch, and will provide more support, than a piece of the same thickness with less density.

    Use an electric knife to cut pieces of foam. Mark your cutting lines first with a jiffy marker. Get one person to hold the piece taut, while the other person cuts on the line. This method makes it so much easier have clean cut lines with less wastage.

    Foam is pricey. Jcraw is quite right that a pre-cut piece to fit the shape and size of the chair above, can be easily pass $150.

    Ask yourself if the furniture item is worth the cost of the replacement foam, fabric, plus your time and labour.

    comment photo
  • Deb K Deb K on Apr 25, 2023

    Hi Sharon, you can take it into a foam shop and they can cut a new one for you.