On the face of it installing new carpet over the old carpet does have some advantages.
Plywood over carpet.
Instead of plywood i am considering using vinyl floor runner over the existing carpet and taping at the seams.
If you are using more than one sheet of plywood tape the sheets together at the seam.
Most other standard types of plywood are treated with a copper compound that will interact with the latex rubber backing of your marine carpet and destroy it over time.
It s a good idea to start from the inside out if you re using adhesive.
Don t even try to put flooring on top of carpet.
Choose carpet tiles that interlock into place.
Wood laminate flooring directly over the carpet.
Using a carpet pad or plywood base over the existing carpet can create an even base for new carpet tiles.
When placing plywood sheets over plush carpet lay them in the opposite direction the floor will go.
I got your questions about putting hardwood over laminate.
This marine plywood is treated using chromated copper arsenate cca which is a chemical wood preservative containing chromium copper and arsenic.
Here s a link to a success story over fluffy carpet if you d like to try it.
Sure i d get my security deposit back but i d have to live with a disgusting 8 x 10 cover up in the meantime.
That means you can t afford to be trapped in a room corner.
Existing low pile carpet can serve as the carpet pad.
A rug over carpet.
We didn t know enough about our future to justify the time and expense.
The important part is to make sure you have that plywood underneath because if not the floor will flex too much.
It saves on the cost and labor of pulling up and disposing of the existing carpet keeping carpet waste materials out of the landfill.
It will need time to dry and you don t want to disturb it.
After putting the layer of plywood over your existing carpet you can proceed to glue the pieces of carpet tiles according to your design or chosen pattern.
Or use special carpeting metal glue less clips that save time and can be rearranged when placing on the floor.
There will be way to much flex and give even with plywood.
After 2 years of some very active kids living on it it has held up decent.
There are some sound dampening underlayments made of cork or rubber to limit noise transmission under wood or tile flooring but it sounds like you have been told no on that already so i think you may be stuck.
Even with that we still have some boards that have started to peel up.