Vinyl Plank Flooring - what goes underneath?

[happyharry12]

Hi - hoping someone here can help since I've received 5 different opinions from 5 different reps at various wholesale flooring sites.

We're looking to install 5mm luxury vinyl plank flooring in our basement, which has a concrete subfloor. This is the floor in case it helps https://www.lumberliquidators.com/l...nk-Flooring-Tranquility-Ultra-LVP5EO/10046476

My question is: Do I need a moister barrier and a separate underlayment? Or will one of those be sufficient, and if so, which one should I get?

Specifically, I was told to get:
6 mil Poly sheeting barrier. This is the link to the exact product
Tranquility Ultra LVT Underlayment This is the link to the exact product

 

[highup]

Basement is your keyword. From our vantage point that makes it much more difficult.
If your basement is below grade then moisture is an issue. How much of an issue we can't tell from here. The only way to tell and to know how much moisture is coming up and out of your concrete floor in the basement is to have someone do a moisture test. Concrete constantly emits moisture vapor. Sometimes very little and sometimes a lot. Usually you can't see this because it evaporates so quickly off the surface, however once you cover the surface with a solid vinyl surface, the moisture can/will build up underneath that material. Tho vinyl planking is waterproof to a good degree, one needs to think about what happens if moisture builds up and stays trapped between the concrete and the bottom of the vinyl planking........ That area is now damp and the moisture just sits there.
Once you have the results of the test then you can decide what will work and what won't.
Lumber liquidators is probably not your go-to choice to decide that. They are volume store and sell products. I doubt they could give you a source of a person that would do a concrete moisture test.
You need to go to a flooring store, a real one, and ask them if they can provide you with the name of some person or business that does concrete moisture testing. Once you know the rate of moisture emissions coming out of your concrete you can make the best decision.
A local flooring person who has lived in your area and installed in your area for their lifetime might already know what to expect from a basement in your area. I'm talking about how damp or how much moisture is coming out of your concrete.
If the area you live in is not prone to high groundwater levels or you live in a dry area maybe 6 mill plastic sheeting might work just fine..... It might.
Like I said it's hard to give an answer without more information.

 

[havasu]

I would roll on a waterproofing onto the concrete. There is moisture between the dirt and the concrete, but roll on a waterproofing membrane, then add a click lock with built in rubber backing. That will stop the moisture, and no mold or mildew will build up under the click lock.

Mapai Aqua Defense is a good quality product