Sarah,

I'm not 100% certain, but I have been told by guys in the field that it's simply best to leave it alone and go right over it. Once you crack the asbestos material or damage it, that's when you've got issues and really should get a hazmat crew or licensed group out there to who can seal the place up while disposal is going on. In a nutshell. . . leave it be and go right over it.

Cheers from Texas,
C

My floor guy says definitely tile over it.

You will want to cover everything in new plywood, and then tiling over the plywood. There isn't much that will go straight down over asbestos/vinyl. Adding a layer of substrate over top of the vinyl (encasing it between layers of plywood).

Thanks Cancork Floor :)

Is plywood best, or could I use a vapour barrier product like this?

https://www.homedepot.ca/en/home/p.plus-tile-underlayment-for-tiled-floors-with-shear-stress-control-164x328ft-rl-54-sq-ft.1000839424.html

@newhomecanada I'm not sure if thinset/uncoupling membrane will adhere because those vct were always waxed as routine maintenance. That isn't a moisture barrier that you have shown its called an uncoupling membrane. Call manufacterer to get answers.