Submitted by Thanossnapp t3_1245spw in DIY
Hey everyone, I have a silly question but I want to make sure I do this flooring correctly. The Vinyl Plank that I have already has underlayment on the bottom of it. In your guys experience should I put another underlayment on my slab concrete as well or anything for that matter over the concrete?
This. I recently fitted some lvt flooring which is about 5mm thick.
As it was going onto concrete subfloor, I decided to add some fibre board under to help it warm things up a little. The instructions said not to do this but I thought the extra warmth would be needed. Well it's fitted now and does have a slight flex to it as you walk on it.
Tbh I wanted a waterproof flooring as it's in the kitchen so the thicker planks weren't really considered, also didn't want to use the glue down stuff as it seemed harder and longer to fit.
I'm kind of regretting it now, but it's not too bad, I just wouldn't do it this way again. I do feel I was right in that the lvt backing is no where thick enough to help take the cold out of a concrete floor.
Really they should make these lvt about 10mm thick to keep the strength in it.
They do make it thicker. 4-5 mm thick is from light commercial/residential product lines. Then they have heavy duty/high traffic commercial LVT which can run 8-10mm thick — But you’re definitely paying for it $$$.
Yeah. I went with 10mm for my bedroom.
I installed my LVP and to get the warranty you have to meet the manufacturers requirements. I bought a waterproof tile with padding built into the bottom and thus didnt need a moisture barrier. But, if I had it in a basement, I would have put one down due to moisture content In conjunction with the manufacturer’s instructions.
Most flooring will have a phone number for support, call them, its free.
You shouldn't need to, and dependent on the brand laying additional underlayment can actually void a warranty.
Wow I did not know that. Thank you!
Depends on what the constructions say
I'm using a vapor/ thermal break on my basement slab
Does the vinyl plank you installing already have underlayment on it?
Yes
It has an ixpe pad built in
Concerning the product waterproof floating vinyl plank or tile floor, it will not leak to the subfloor - by the same token, condensation from the concrete will not rise through the seams.
I want to keep the room as comfortable as possible. The concrete was poured in the 50's it's far from laser level. I figured the thermal break and the extra padding would help not to mention sound deadening.
Most manufacturers recommend pouring a leveling compound first in order to prep the floor. if there is too much deviation, it will cause the joints of the planks to separate over time and ruin the floor.
No! Quick answer, but vinyl is too thin for any kind of underlayment except ones specifically made for vinyl, which, of course are the more expensive kinds. If the underlayment is not made specifically for vinyl, it will be soft and compressable, which allows the vinyl to bend and move and lose all integrity of the seam lock.
I wish I'd have seen this before I did my kitchen🥹
I think you have your answer about additional underlayment (no), but just wanted to chime in about leveling. Make sure you or your contractor do all you can to level the floor under the vinyl. Peaks and valleys will cause the same type of movement in the joints, and will be very visible in the final product.
Thanks will do. So i now see additional underlayment is a no, but a vapor barrier ok?
Vapor barrier should be fine
No extra underlayment needed. Level the floor and add a vapor barrier then install.
Thank you thats what I was gonna do I just wanted to make sure I wasn't missing anything or there wasnt any tips or tricks
No extra needed. Just laid about ~1000sf of 5mm LVP in a finished basement and followed manufacturer instructions (although I was scared since I was laying onto concrete subfloor). Floor came out great and all I put down was a vapor barrier (thick plastic) and to my surprise, it doesn’t feel cold at all like the tile that’s in the basement bathroom 🥶
We had some LVP installed last year and the installer followed the manufacturers directions, which didn’t require underlayment. We started getting peaking between planks do to hydrostatic pressure. Manufacturer has since changed directions and requires it now. Still fighting with manufacturer to replace our flooring.
Don’t use underlayment unless the manufacturer allows it. If something happens the mill will deny the claim. Get something with backing on it so you are within warranty and you save a bit of money.
generally underlayment is to prevent the absorption of moisture. Vinyl plank doesn't have that issue so I would not.
follow instructions on box...
Yes! Underlayment is cushion as well as moisturizer barrier and prevents planks from squeaking. It also protects your planks from any imperfections in slab. Better quality means longer life and comfort. Your feet and back will thank you because shock absorbance from premium underlayment.
This is extra, super duper incorrect.
Follow the manufacturer’s directions- more padding means more motion at the joints, and very quick failure for many major brands that already include an underlayment on the planks
Source: did the same room twice last year
123isausernameforme t1_jdydioy wrote
Follow the manufacturer directions for the specific product. I do this for a living, generally I don't use a separate underlayment as I feel it's unnecessary. But directly over a basement slab I'd do whatever the manufacturer recommends.