How to put new foam in a 3 seater sofa?

What type of sofa? Some have zippers in the back of the cushions. Does yours?

Hello Mike, hope this helps you, most sofas have hidden zippers,

https://www.youtube.com/watch?v=9zlvV1tOEGo

As Naomie said, if your sofa has zippers, unzip and stuff in your foam. If no zipper, go along where the cushion is attached to the frame (back of the cushion) and very carefully slit the seam open and stuff. Resew that seam with a curved needle designed for sewing upholstery.

Hi Mike,

If the cushions have zips ,that's the way to go. If not you will probably need to deconstruct the upholstery to replace it. Start at the bottom edge. You will need tools and Staple Gun to replace it. Best wishes.

Do you have loose cushions or are the sewn into the couch?

Here is a tutorial AND how to video I made on that topic! https://www.charlestoncrafted.com/stuff-sofa-cushions/

We had the same problem with our customized leather Natuzzi sofa. The retailer repaired it the first time which made it too hard and stiff.

We have worked on it since. Flipping the sofa (in our case its a separate module the sofa snaps together in two pieces) over you can remove the dust cloth staples to remove this cover and expose the sofas internal aspects. A piece of wood could be screwed in the structure to help support the cushion -preventing the sag. Adjust foam cushion to your need. Then the dust cover needs to be reapplied with a staple gun.

If you are planning on replacing the foam here are some tips for cutting it.

Quick tip re foam: If you need or want to replace the foam (check first whether it seems to be the foam that is the problem or whether the springs or support of the sofa is shot) then you can cut your own foam if you mark it up first (measure twice, cut once!) using an electric kitchen knife. Please don't use scissors or shears as these will twist the foam as you cut and you will end up with crooked or jagged edges. Foam is not cheap to buy, so if you are going to cut it yourself, make sure you can cut it straight!

Most cushions have a zipper but if they don't you could add one or velcro to them. Carefully take apart at the seam. You may need to add a bit of material if it won't meet. Make sure to do this on the side that is against the sofa.

Another thought is your issue may be the support on the sofa. My SIL bought a set from someone for $50 that he said needed new cushions. We put plywood under the cushions and problem was solved.

All foam is not created equally.

When replacing foam for any furniture that is going to be sat on, such as sofas or chairs, there are two main considerations:

1. the thickness of the foam
2. the density of the foam

These are not the same.

While thickness generally provides the soft feel, it is predominately the density of the foam that provides the support to bodies sitting on the furniture, and helps prevent sinking down.

A piece of foam with more density and less thickness can provide more support than a piece of foam with less density and greater thickness. The quality and the price of the foam are also factors in how well a piece of foam might retain its supportive ability.

https://www.youtube.com/watch?v=els9ytDVTE4

https://www.youtube.com/watch?v=ZAMEhG3WwYI