Luxury Vinyl Plank Flooring Over Tile in Basement

Question

I've been reading up on whether I can lay LVPF over an already tiled basement, and the consensus seems to be that I can so long as the grout isn't too wide/height differentiated and the ground is level.

I'm reading some LVPF brands and see that some say not to lay it over tile if it's applied over concrete below grade. I have no idea what's under the tile in the basement. I would hope there's some kind of vapor barrier and the tile on that if it's directly on the cement slab. But I have no idea.

Should I be worried about this? Could I mitigate it with an extra vapor barrier or something? I'm doing the poly sheet taped over the floor for 48 hours test now to see if there's any vapor leakage. But it's generally pretty dry down there.

EDIT: Added photo of where the tile meets the door frame and the unfinished laundry room that has what looks like painted linoleum.

Answer 1

Much LVP has its own vapor barrier. However you don't want to trap moisture under the new flooring.

If your polly sheet shows it is dry, go with the LVP right over the tile.

What is very important but often overlooked is the thickness of the LVP. The thicker the product the less it will flex. This transfers to less likely to have issues with unevenness and grout lines.

The problems with the flooring having seams coming apart and/or being wavy because of a less than perfectly flat floor are the results of a thin product. Thin products have less resistance to any flex during use. Generally thinner is less expensive, so you get what you pay for.

How thin is too thin? My recommendation is to avoid any product not at least 5.5mm. I have installed 5.5 over tile with no issues. Used 5.5 and 6.2, 6.5 and 7mm over concrete, plywood, tile, linoleum, wood plank and vinyl tile. All done with no issues.