moisture barrier under LVP

[laser3kw]

Kind of related to garage floors I guess.
I also am doing some remodeling in our house. We have a small house so all the 25yo carpeting and vinyl tiling is coming out and we are having Luxury Vinyl Planking installed. The planking is 6mm thick with a 1.5mm backing.
Our house is concrete block on a slab. I am looking for recommendation and / or education on a moisture barrier product to put down. I have seen plain black plastic, thin foam sheet, silicon, and some featuring thermal and moisture barrier. Being in the frozen north, I would think a thermal/moisture barrier would be the ticket. But I know nothing about floors.
Any recommendation?

 

[PCustoms]

What do the install instructions call for?

Typically anything else will void warranty.

Is your house typically wet? With carpet coming out I'm assuming the floors were dry.

 

[laser3kw]

I am putting together the list of materials to buy.
Our house is typically not wet. I will know more once we pull up the existing flooring. Moisture barrier is recommended by the manufacture of the LVP. . My research shows different takes on moisture barriers. I am trying to find a goldilocks product - not too thin. not too thick, not too expensive, not too cheap ect

 

[duneslider]

The manufacturer doesn't have a recommendation on what to use for the vapor barrier? Usually they will specify something like 20mil poly, or something like that.

 

[laser3kw]

minimum 6mil poly. There is a very diverse array of products that all fall under the heading of moisture barrier underlayment. Some times more is better, sometimes not. Obviously, a house down in Florida will have different requirements than a house in Wisconsin. The logical side of me thinks a product that has a moisture barrier and, perhaps, a thermal insulating quality. Because it is a concrete slab, I don't need a thicker felt product because I don't have to worry about sound transmission. I have read where a simple poly sheet (similar to a garbage can liner) might allow the floor to slide over time.
Any flooring experiences will help
thanks

 

[jbtvt]

Vinyl is waterproof so unless your basement floods, in which case a vapor barrier wouldn't matter, you won't need anything. Plastic over concrete below a thin, flexible floor that's also susceptible to expansion and contraction on its own will wear though in no time. A thermal foam barrier won't help with comfort, vinyl feels cold no matter what, although closed cell might keep some moisture out. I helped a friend put down a very basic LVP many years ago on a bare slab that has flooded once in a while and no water damage, although it does scratch and looks like vinyl. I went with a cheap tile in my basement. About the same cost, took weeks longer to install, but looks better, 100% waterproof, and will never need to be touched again. Pros and cons to both.

 

[laser3kw]

Pros and cons to both.

Thank you for your experience.

 

[duneslider]

Moisture won't hurt lvp. If they call for 6 mil then that is enough, you can do thicker and it won't hurt anything. You already have a "pad" attached so I don't think you will see any benefit to using a felt or more pad under it. In fact most manuf won't warranty it if you do add more pad. Also, anything you add such as pad, or foam, or whatever won't make the floor warmer. Unless you add a couple inches of foam board under it, then it might help a little but will still feel cool to the touch.

I too love tile but the wood "look" of lvp is superior to the wood "look" of tile. Obviously, pros and cons to every flooring option. Tile is much more permanent and statistics show that very few homeowners like permanent flooring. Most kitchens for example are completely remodeled in about a 10-15 year time frame...so the easy install, easy removal is a popular thing.

I don't think I have ever had a floor slide. Sure, when you are starting the job the first few rows can be a real pain to get going and want to slide but once you have a few rows down I pile the heavy boxes on it and it doesn't slide anymore. Once the floor is all down is doesn't move, you have to remember that the weight of that floor over even a whole bedroom is hundreds of pounds. LVP seems to have a similar density to steel, its heavy stuff.

 

[mike93lx]

I did laminate with a poly VB under it in a basement. No issues with it sliding, once I got it installed. There were a couple spots that the floor was a little low, and you could feel some give when you stepped on them.

FYI, that floor is going to feel a lot colder than it does now. I did 1/4" foamula under it and it helped, but was still far from warm.

 

[slimpickins]

Deleted

 

[laser3kw]

I have had a couple of recommendations for a cork product. After reading more about it, it may be a front runner. Won't slip like poly, some thermal benefits, moisture resistant, sound deadening, anti-microbial. I am intrigued.

 

[duneslider]

Cork is pretty dense but is still considered a pad and most manufactures that have LVP with the attached pad do not want you using additional pad under it. The tongue and groove on the lvp can break off if there is too much movement. I have used cork underlayment with lvp a lot and it is great but if the lvp has attached pad you don't need any more pad.

I think you are way over thinking this.

 

[Toyo72]

Cork is pretty dense but is still considered a pad and most manufactures that have LVP with the attached pad do not want you using additional pad under it. The tongue and groove on the lvp can break off if there is too much movement. I have used cork underlayment with lvp a lot and it is great but if the lvp has attached pad you don't need any more pad.

I think you are way over thinking this.

This is spot-on. I used a better quality LVP from Flooret (Modin Signature) in our house and and just finished in our barndo-shop. The LVP has an attached pad and the manufacturer recommended against any type of underlayment or pad, but did recommend a moisture barrier since the install was on a concrete slab. I used a 6 mil poly sheeting from Lowes, which comes in rolls of 10' or 20' wide widths.