here is how I added padding to a sofa - https://www.charlestoncrafted.com/stuff-sofa-cushions/
outside chaise or inside furniture?
I followed these instructions listed on the videos. Good luck to you Jill.
Many chaise cushions have a zipper or simple seam at the back which can be opened. Take out the current cushion forms and shampoo and dry them in the sun if possible. Buy foam padding (fabric store or department) of the thickness you would like to add to the cushions. Buy a little extra width because you will be filling corners and curves. You might come out better buying a single-bed egg crate mattress topper for each chaise lounge.
Return the original cushions first, stuffing them from the top, and fitting the original form as much as possible.
Then cut the foam into pieces about the size of individual sections, plus at least 4-8 inches on each side. Pack the sections from the bottom, filling each curve and corner as you go. If you need the use two pieces of foam instead of one, fill in the sides first and let the cut sides butt up against each other, on the bottom. Fluff the chaise as much as you can. But since the chaise cushions are now overstuffed, you can’t fluff much. However, the cushions should be firm enough to give you much more service.
Mince you get the hang of this, you may want to resting all the upholstered furniture in your home. Best wishes!
A tip, when restuffing the cushions, I always do this with damp cushion cover as it has more give to get around the expanded stuffing.
Buy some out door cushions
Buy some thick cushions. If you have an At Home store near you, they have outdoor cushions for a reasonable price.
Undoubtedly material,or replace ,buy new foam,or if expanded foam inside covers,try steam heat or steam cleaner