Thank you good people for responding to my sofa dilemma. Most of you suggested a plywood insert. I understand your reasoning and that has been tried and it’s not as comfortable as this foam is. Plywood feels like you are sitting on a cushion on wood……. Problem: new foam cannot be added to cushions.they are fine and completely stuffed. I need to find a way to insert this foam under the cushions in one piece. Should I open the lining under the cushion after I have trimmed the foam? Or should I just trim the foam in front, back far enough so that it doesn’t show? Have I gone over the edge and have lost my mind?
if I could find a way to slip this foam on the top of the springs……that’s what the sofa needs. But, I’m afraid I won’t be able to put it back together if I remove the fabric covering the springs. Has anybody ever tried this? Don’t be afraid to admit that you did and tell me how it worked.
Are you trying to prevent sagging or something else? More info please.
As you have it but cover in same or contrasting fabric to the couch (Maybe the colour of scatter cushions. Make a tube and then ttuck in the ends. If you want to make the seat firmer you could add a board of MDF under the cushions.
Hi Ginger, so you want the foam in the picture to look better? You can trim it to fit the couch nicer, and put a cover on it, that closely matches the color of the sofa itself, find the fabric you like and hopefully this video helps you out
https://www.youtube.com/watch?v=zhcEe3z0kig
Are you trying to bring up the cushions so they're higher? The foam under it now looks like it is a little too thick and it is bringing it up too much. Could you maybe try a back pillow instead of better comfort?
You can add a layer like you did in the picture, but find a thinner one. You also may want to cover it in a matching fabric.
You can cover the foam with material that stretches to the back of the pillows. Make a hem that is folded over for strength then staple the to the back frame. Put foam down then pull material up and over it and staple to the frame again creating an envelope for the foam. Make side seam before you put on the couch to have a finished edge.
I think your issue may be needing support rather than foam. Try cutting a piece of plywood to fit beneath
Hi Ginger, looking at your picture the cushions look pretty firm so it may be a question of sagging spring or no support underneath the cushions. Have you tried adding a board between the cushions and the couch?
The only way to do that is to add the foam under the pillows - and that may not look so great. You could try adding a board to prevent further sagging: https://amzn.to/3DUx2Zi
Keep in mind that upholstery foam varies in two main ways - its thickness, and its density. These are not the same. For sufficient support both inside the cushions, and underneath them, you will want to choose foam that has adequate density.
https://foamonline.com/blog/differences-similarities-between-foam-density-weight-firmness/
https://www.youtube.com/watch?v=BFK0o9W-loE
Looks like you need stiffer support than a piece of foam under the cushions can give you, a sheet of plywood would be the most practical way to solve this vs entering the underside where the springs are, undoing them and adding foam and re-attaching them.
You can cover the foam with a leather looking vinyl fabric that matches or coordinates with your sofa. They sell it at most fabric stores and you can use a spray adhesive.
If the height is the problem add something under the legs to raise the height.
Check this https://www.pinterest.com/search/pins/?q=how%20to%20add%20foam%20to%20couch%20cushions%20diy&rs=typed&term_meta[]=how%7Ctyped&term_meta[]=to%7Ctyped&term_meta[]=add%7Ctyped&term_meta[]=foam%7Ctyped&term_meta[]=to%7Ctyped&term_meta[]=couch%7Ctyped&term_meta[]=cushions%7Ctyped&term_meta[]=diy%7Ctyped
Yes, I have gone under the couch and added foam by slicing the bottom covering and jamming the foam above the springs. I’ve also done it to a recliner.
I have also used the plywood under cushion idea. If you place it under the cushions, but on top of the couch frame, it will firm the entire couch. If you only place it on top of the springs, it will firm the cushions and not feel so much like sitting on a board.
It sounds like just the springs are the issue. Set the couch on it’s front, cut the bottom material all the way off, stuff away! Obviously you will need to use pieces of foam, not the full length at once. You might try firm pillows first. They are easier to work with because they’re covered.
When you are through, buy replacement fabric for the bottom of the couch and staple it on.
If it just the height why not raise the height of the legs?