How do I prepare knockdown walls for peel and stick tiles?

As I said in other posts, you really cannot combat gravity by placing vinyl directly on a wall. Yes people recommend it, but this is rarely durable. As with Anything you plan to fasten to a wall, it is most durable when fastened to Studs. Really, unless it is a Panel, you should heed that Generalism at all times.

So, as what you are really accomplishing is creation of a DIY Panel, you will need to instead place and glue your tiles first on something like Plyboard, Polyboard or Sheet Masonite, while it is lying flat.

After that Panel is made, and all is set, you then can fasten the Panel just like anything else with a Decent Glue like Gorilla Glue or even permanently mount it, by screwing it into the Studs or make it removable just like any Access Panel (to Access Plumbing or Electrical), by attaching with Anchors and Screws.

In an Apartment, removable is recommended.

If you own it, permanent mount is recommended.

Be forewarned...if you put peel and stick tiles directly on your knock down walls you are never going to be able to get them off without some major wall damage when you decide you no longer like them.

Your wall needs to be smooth or covered with something that is smooth. I have eliminated texture by applying a coat of sheetrock joint compound and troweling smooth. Some sanding required.

Hi Leslie, hope this helps you out,

https://www.ehow.com/how_12204213_install-wall-tile-over-textured-paint.html