So, basic gist is my wife and I just purchased a Parklane foam mattress (Seneca), and we’re excited. Our old mattress was a S&F (I believe) pillow top innerspring that has broken down to the point of noticeable body impressions.
We’re going to put the old mattress in the spare room for a guest bed.
Would it be easy and/or feasible to cut the pillow-top off the innerspring core and lay down a latex or memory foam pad on top, and then cover it somehow?
Hi mnmenthttt,
Mattress surgery can be a great idea and the innersprings will usually still be fine because the foam over it is the most common weak link of the mattress and will break down long before the innersprings do.
There may be some layers inside the mattress that you decide to keep and there may be some that you remove besides just the quilted cover or pillowtop. The specific approach you take about what to keep and what to remove will depend on what is in the mattress. Most people are very surprised at the low quality of foam that is inside their expensive S&F and remove most if not all of it … but of course there’s more to replace that way and it may be worthwhile keeping any better quality and firmer polyfoam inside to reduce cost.
It’s also very important to make sure you keep the mesh or insulator (depending on the mattress) on top of the innersprings to prevent the foam from migrating into the springs.
There’s a few threads here where people have taken pictures and described their mattress surgery which may be helpful.
There are a couple of things that these threads didn’t mention though that I would also consider. Most have removed the pillowtop completely and those that didn’t left it loose rather than re-sewing it to the border and this can leave the mattress too exposed to air with only a protector or pad over the bare foam. This would likely allow any latex in the mattress to oxidize and break down prematurely and I would try to make sure I used a high quality fabric cover actually sewn to the sides for long term use (this wouldn’t be a problem for short term). In the factory they use what’s called a tape edge machine to do this to reinforce the seam.
Another possibility would be to buy a completely new zip cover that was the right size and type for your final layering rather than going to the difficulty of trying to re-sew the top to the sides. This way you could put all the components into the cover and zip it up and have a finished mattress.
I would also consider talking to any local manufacturers near you who may be willing to rebuild the mattress for you using your innersprings and choice of foams. They would also be able to use their tape edge machine to properly finish it once it worked the way you wanted it to and would probably give you some good advice as well.
Overall I think it’s a great idea and I think it would be a rewarding DIY project 
Phoenix