Best way to install vinyl snap lock over concrete?

[Harrity]

I'm about to take on a flooring project and could use some advice. The plan is to level out the concrete foundation and lay down vinyl snap lock planks but I dont know whether or not a subfloor is necessary for this. I've heard that you can float it directly on the foundation as long as it will be flat and clean, while others recommend putting something in between for insulation, moisture, and comfort.
So please if anyone has done this before, did you go straight on the slab, or did you add an underlayment or subfloor? or if you just have knowledge about this

 

[mamamew]

While it is technically possible to lay vinyl plank flooring directly on a concrete slab, it's not usually the best long term solution. The primary reason for an underlayment is to act as a moisture barrier coz concrete can hold a lot of moisture and release it into the flooring over time. Even if you think your slab is dry a moisture test is always a good idea. Another benefit of an underlayment is sound dampening and adding a little bit of comfort underfoot. Most flooring professionals would suggest putting down at least a basic moisture barrier and a thin foam underlayment to protect your investment and give a better feel to the floor.

 

[slvr22_bd]

I'm about to take on a flooring project and could use some advice. The plan is to level out the concrete foundation and lay down vinyl snap lock planks but I dont know whether or not a subfloor is necessary for this. I've heard that you can float it directly on the foundation as long as it will be flat and clean, while others recommend putting something in between for insulation, moisture, and comfort.
So please if anyone has done this before, did you go straight on the slab, or did you add an underlayment or subfloor? or if you just have knowledge about this

I second what @mamamew said. Direct-to-slab is technically possible, but not ideal for the long term. The absolute priority is moisture. Concrete is always wicking it up, and that moisture will compromise your vinyl planks over time. A moisture test is a smart idea, but regardless of the results, flooring professionals always recommend at least a basic vapor barrier underlayment. Beyond protection, the underlayment provides a crucial thermal break and cushioning, making the floor warmer and much more comfortable.

 

[purdil21]

Put down an underlayment to help with minor imperfections, and can even act as a moisture barrier. If your concrete is really level and you don’t need extra insulation, skipping a subfloor is not bad, but underlayment is a nice safety net