It needs to be flat, not necessarily level. The flatness is so the flooring makes 100% contact with a solid surface and does not flex, which would lead to breakage. It very well may void your warranty from Coretec if the floor has not been prepped properly if a warranty is imprtant to you..................................

Thanks millworkman. I emphasized that point to the contractor, which is why he has offered to take over the warranty - because he is "confident." He and one of his installers also tell me "It's a 'floating' floor - they are supposed to 'float' over the slab." To which I remind him that there is a limit to how much float is allowed, and that it stresses the joints.

I'm just curious what others' tolerance is for this sort of thing. Right or wrong, I wonder how many folks are living and loving their basement LVP on a less-than-perfect sub floor? Because to hear our contractor, he installs many LVP floors with no complaints...

We're also tired. This has been our year of home improvements, and we are weary from project-management! But I also don't want to be bothered by the floor indefinitely.

>>>following as we will be using a LVP in the laundry & mudroom here, but it is over a plywood sub floor>>>

I put in the Home Depot brand which sticks together, not click&lock. I did it myself over a floor that was far from completely flat or level. It's a play area, so it gets some abuse from the kids, but at the same time I did it myself so it would be cheap and I didn't expect perfection. It's held up fine so far (a couple of years almost). You can definitely feel where the hollow spots are, but no breakage as yet.

Cheryl, for what it's worth, I think LVP on a decent plywood floor has minimal issues - if installed correctly. Concrete we are learning, is much more likely to be uneven, which then leads to noise and other floating floor unpleasantries. I can see that our flooring was installed well (barring the offensive pattern repeats from single-box pulling); it's the sub-floor prep that suffered.

@RH- I should not be to worried about it, as hubby & our worker will be installing it & it is the 2nd house that we have built,but the last one was 26 yrs ago. this build is an ICF house with timber frame/beams. Right now they are working on the kitchen/foyer tiles. Hubby is a Mechanical Engineer & has dealt with many commercial projects/builds over the years. our pile of LVP for the areas.

you should go have a look at my profile page & look under new build/gabe for some photos.

https://www.facebook.com/photo.php?fbid=10160928145070107&set=gm.675284349486679&type=3&ifg=1

Tell your contractor you'll live with it as is for a year as long as he'll guarantee it for that long in writing. I'm betting you won't be calling him back.

Sub-floor flatness needs to be 3/16" over 10' or better. You are allowed deflection, no more than 1/8". That stays within the mfg's tolerance for flatness. Screeding with a 10' straight edge is the easiest way to get a slab flat. Most rooms are 10'-13' wide.

Core-Tec technical department told you what? Were they willing to send a inspector so you can have a report in writing? Are you gathering opinions or looking for facts? Only one source for the proper answer. Call the manufacturer and post their response for others to learn.

G & S - It's a great room that flows into a bathroom Pic below. The info. about deflection is useful. While I've seen the many iterations of 3/16" level or 10', or 1/8" over 6' etc. - I haven't found any useful info. in CoreTec literature about deflection or the amount of "float" tolerated over a void.

Creative Tile - I'm mostly looking for opinions that will help us make a decision on whether to live with it as is and a warranty from the contractor, or whether to tear it up and likely create new headaches.

At this point, I am well-versed in CoreTec's literature and ideal LVP installation standards. Our floor doesn't meet them. I'm just curious how many people actually have perfect basement floors for their CoreTec, vs. how many are happily (or not) living with the imperfections. It seems like a truly level basement slab is not a common thing.

Pulling our entire floor will likely ruin a lot of planks (several planks area already damaged because they were pulled from around our toilet flange, which had self-leveler applied to the slab today because it was so bad).

Some photos...

Bathroom is rear back corner. Flooring already pulled there. Flooring does not enter the two storage rooms. The next worst void is all around the white support pillar. A lot of flexing in the floor there.

One of the areas with multiple pattern repeats that drives me a bit nuts, but it would be covered by an area rug.

Sorry for typing a novel! Lol.

Again, I'm just looking for perspective of how bad, or not-so-bad, my options are. Feeling rather stuck between a rock and a hard place. Thanks Houzzers!

Understanding flatness and it's tolerance. When a flatness of 3/16" over 10' is called for. The high spots and low spots cannot exceed the dimension or tolerance given - 3/16". In a 10' span, a floor surface can have "several" high and low spots within the tolerance given. Therefore, a flat surface is never flat. It still contains waves and variations within the tolerance called for. The tighter the tolerance, equals the flatter the surface. If, you have a bounce or deflection, it should not exceed the maximum tolerance given 3/16".

A lot of installers will drive themselves nuts, trying to chase perfection. Not having a clear understanding of the tolerances and how to apply it.

The contractor said he "will warranty the floor".............yes? Are you by any chance an engineer by day? : )

"At this point, I am well-versed in CoreTec's literature and ideal LVP installation standards. Our floor doesn't meet them."

I'll just leave this quote here........................

There are also several other posts here in recent days with major issues from floating floors either not installed properly or no proper floor prep. You may want to read them.

RH - not sure if this is helpful, but we are in the exact position as you, trying to decide on a floor suitable for our basement.

We too have a concrete slab that we've been told is "pretty level", whatever that means. We are strongly considering LVP based on it's waterproof properties. However, the more I'm reading about it, the more I am afraid it is not the best material to put on a concrete slab under grade.

We too have looked at CoreTec (click and lock) and it was/is on the list of finalists. I've spoken with a couple of coworkers and friends who have LVP on concrete slabs, both above and below grade, who have complained about hollow spots. They've compared it to having a squeaky hardwood plank that gets on your nerves; some people have a lower tolerance than others for these kind of things. But I think the problem with the hollow spots in the LVP (vs a squeaky board) is that they're at risk of breaking (I would think if the pressure gets great enough it would cause two boards to pop up) then you are in a pickle.

One of my friends really hates these hollow spots and is ready to get new floors. The other is more meh and realizes no floor is perfect.

So I don't know what I would do if I were you. Any kind of floating floor is going to have hollow spots if the floor underneath isn't level, I would think. There is a huge chance of planks breaking if the floor is removed, and I'm guessing then that cost is on you to replace them. I don't know how much you'd want to live with.

Our inner office at our main location is roughly 400 sf. The slab is horrible!! Definantily not flat! We installed Coretec to test it over the unlevel, not flat floor. 2 years later, yes you feel the humps and dips in the slab but the Coretec is holding up excellent! Mind you, we also have roller chairs. The roller chairs have not scuffed up the flooring or caused any damage.

Don't do as we did, it will void warranties. We installed like this to see how it handles the abuse.

All other installs we do for customers are by the manufacturers installation instructions. Have never had any issues when the steps are followed correctly.

Hopefully your contractor doesn't change professions down the road. Coretec, if installed properly, has a limited lifetime warranty. Limited in the fact that the warranty will not transfer to a new owner. With a manufacturers warranty, it doesn't matter if the seller goes out of business because the manufacturer backs up their product. That's gold over a contractors warranty any day of the week.
Good luck!

If I may comment about the contractors "educating" the homeowner suggestion. In my experience (6+ years in the flooring industry) I have found only ONE General Contractor (actually a PROJECT MANAGER = HIGHER PAY GRADE) who was a Mr. Chatty McChatty. The rest of the HUNDREDS of subs/contractors out there are there to get in, get out and get gone with everyone being "happy-happy".

I'm sorry but the building industry rarely includes SUPER chatty people. The sole exception being the person mentioned above. And his company specializes in Design-Build projects of $2M - $15M in Metro Vancouver. Needless to say he does A LOT of hand-holding. And he doesn't mind because he's just that type of guy (nicest guy you will EVER MEET!). He has to be. He's going to be in your house and in your life for 1.5 - 2.5 years.

The only other two people I experienced as being "chatty" were two female "handy-gals" who ran their own renovation companies - specializing in smaller projects. Again, being who they were, they always wanted to know the BEST way to do things and would take the time to reach out to the manufacturers to find these things out.

As you can see, the "educate the homeowner" is not something that happens. I'm sorry to say this as I think this is a fabulous industry to get into (someone who is smart, educated, likes working with their hands and has INTEGRITY will make an absolute KILLING in this field).

I wish more professionals took the time to spell out EVERYTHING that can/WILL GO WRONG to the homeowner. But that backfires. The professional who CAUTIONS a homeowner about a project is the professional who gets very little work = out of business ASAP. So they have learned to zip their lips and do what they are told.

In your case, you DID ask about leveling the concrete slab. I would suggest looking into the PRICE you paid for concrete preparation (was it $0.50/sf or was it $3/sf?). And if there was ANY price paid for preparation, I would ask for it back.

The "lifetime warranty" from the builder is probably going to get you 10 years worth of anything. That would be a realistic take on the situation.

I really do wish you luck. I hope you can love your floor. It will probably do just fine. I understand about having a life and living it at the same time. Getting the "most for the least" includes the most "backup for the least amount of effort" can be worth more than just a few dollars in the bank. It can mean peace of mind. And peace of mind is priceless.

R H, would you please give an update on how your floor has held up? I am a first time homeowner who hired a flooring installer (with decades of experience) who did not educate me on anything regarding LVP beforehand. Now that the work is complete it looks done well, though there are a couple of bouncy spots that "pop" when stepped on. Having done extensive research at this point it is obvious that the installer did not take care to prep the concrete floor in my basement; and also tried to deter my questions/ behave as if I were difficult along the way. Please let us know how the floor is performing three years out. Thank you!

Hi mandicat62,

Our floor is still holding up. That said, it's not a high-traffic area since it's in our basement, so I wouldn't expect issues to arise yet (if they do). We purchased a treadmill over the winter and I was a bit worried about the extra weight and bounce on the LVP. Time will tell whether that exacerbates any problems. The floor does look nice, and I think it's a great option for basements, if they can be prepped accordingly.

I'm sorry you are experiencing a similar problem with your floors. It's frustrating when you spend a lot of time and money, only to worry the results won't last. Only you can decide how *bad* the problem is, and how much you want to pursue it. Maybe tell your installer you want a warranty in writing from him against issues related to inadequate subfloor, since he must be so confident the product was correctly installed?

Best of luck to you.

Hi RH and mandicat62, I stumbled across your posts as I was trying to figure out what to do in my own basement. Just had a very similar situation where I spoke to the contractor ahead of time about my concerns, he pushed them aside and said that he does the LVP floors over concrete all the time and it would be no problem, and to my frustration I’ve ended up with several very soft spots in my floor. A couple of them you can see the LVP move (probably 3/8” of an inch or so) and one of them has a little squeak to it. I haven’t figured out what to do yet as tonight is the first time I’ve seen the finished product, but the contractor is basically saying that tearing up the floor would damage a large number of the planks. And of course hes saying he wouldnt be responsible for any breakage.

I’m considering something like what is shown in this video, because I know the flex and the noise will absolutely drive me nuts. Curious if anyone’s tried some thing like this.

https://m.youtube.com/watch?v=-MGA3cyLJBc

Seems risky, but I know I won’t be happy with it as is.

Hi RH,

I just experienced the same problem! The room is the family room, it's 3 steps down from the kitchen, so it's not a basement. But it's also concrete subfloor and I noticed a 4x4 soft spot/flexing and am SO UPSET ABOUT IT. However, fixing it, according to the flooring company who put them in, would require pulling up all of it, including the bathroom and laundry room.

RH, can you comment on how noticeable it is for you? Has the area weakened or broken at all? Is it still holding up or is it getting worse? I am SO SO upset about it, but not sure if it's worth it to pull it up (original flooring guy refuses to do it/pay), or whether to just leave it...

Grey Greenwald-I saw that video too. I was told by a flooring expert that using that type of filler isn't good because it's an adhesive, and LVPs are meant to be floating. I also wonder, if you drill holes, does that reduce the integrity and strength of the floors and make them more weak?

RH, Would like to hear your comments 4 yrs later. My "waterproof" LVP with foam rubber backing was installed in basement apartment that has a 4" slope from one corner to the other and numerous slight dips. (Was probably finished by eyeball with a 2x4 and a bull float.) The temperature and humidity are well controlled, and the floor gets almost no direct sun. After a year and a half, nearly all the planks show some cupping, from slight, to broken edges and actual separation in others. Did you encounter this? and if so, what have you done?

https://photos.app.goo.gl/9Ux23a3QaQRdy2Gy7

Just had mine done 4 months ago and I never had any issues with my previous Laminate floor. Only got new floors due to a pipe burst. Regret getting LVP over Laminate. I got Lifeproof stone core lvp 6.5mm, 12 mil planks and I feel floor imperfections too much. The Home Depot contractor said my floor is within specs, but i doubt it Only time will tell. I cannot recommend LVP as a floating floor on concrete. Stick with a waterproof Laminate. But in a basement I would just finish the concrete and throw some area rugs down there.

Read the product warranty. if it isn’t installed according to manufacturer specs, to the letter, they can and will weasel out of covering your flooring under warranty.

Also, there will be some damaged flooring if you pull it, so make sure you have some extra. It may not be a lot if you’re careful, but the flooring joints do connect very tightly and at least a few edges will break or the vinyl will protrude upward slightly.

Read the product warranty. if it isn’t installed according to manufacturer specs, to the letter, they can and will weasel out of covering your flooring under warranty.

If the installer wants to give you a warranty, that’s great but keep in mind that his warranty isn’t going to be that long (maybe a year or two). You may not see issues for several years, at which point it might be too late.

Also, there will be some damaged flooring if you pull it, so make sure you have some extra. It may not be a lot if you’re careful, but the flooring joints do connect very tightly and at least a few edges will break or the vinyl will protrude upward slightly. I learned that the hqrd way. 😬

We DIY’d our vinyl plank floor over uneven concrete and there are a few spots where the planks came unlocked and protrude. I trip over one at least once a week. Make the floor level before installing them.

Hello,

I haven't visited this thread in a few years, but recently received a notification so figured I'd give a five-year update: Thus far, our floor is holding up. No cupping, warping, etc. The Coretec product itself seems great. Again, our basement does not get a ton of traffic or wear and tear. We also run a dehumidifier in the summer and keep it fairly warm (four-season climate here). No direct sunlight. We use Zep cleaner in a spray mop as needed and that's about it. I still worry a bit about longevity over the unlevel spots, but I don't really notice it anymore. Having it fully furnished with rugs, etc. helps too. The floor does get a lot of compliments from others. Good luck to everyone who goes down this path. It's hard to not get stressed when spending lots of $$ and managing home improvement projects.

Yikes, we just had a local Flooring Contractor begin our flooring project. We're replacing the carpet that was original to the home, and ripping out the tile in several areas to install LVP over slab. The Contractor talked a great game, telling us about his 15 years experience and his "5 Star" reviews. When I asked about getting the old carpet glue up, he assured me he had a "power scraper" that will take the glue right up. Asked about filling nail holes from tack strips, he said he had self leveling stuff to fill those.

My wife and I knowing we were getting new flooring began removing old carpet and tack strips where accessible. I filled the little craters left by pulling up the tack strip and scraped up what I could with the glue. Figuring this would save some time for the contractor.

Well when it came to do the actual prep, he suddenly changed tune saying he's never fills those hole in the concrete it doesn't affect the floor at all and is a waste of time. I can see that might be true with the small holes, but pulling up the tack strips left from pretty sizable "craters." The next "red flag" was when he changed his tune on scraping the glue, he claimed the underlayment would take up any imperfections and we'd never notice once the floors are in. He said something interesting, when he said that when he's installing he asks himself if the floor will feel good under foot to the customer. Which we took to mean, if the customer never knows he didn't do a proper prep or follow manufacturer installation requirements, it's a win.

When it came to following Manufacturers installation procedure, he claimed that's just CYA stuff and he does it his way. Running the underlayment perpendicular to the direction of the LVP, nah, he said you don't really need to do that, besides it takes more time.

Then there's the logistic accommodations we went over with him from the get go, due to our pets. He agreed to 3 phases...until he began work then he suddenly claimed he never agreed to 3 phases, just two, then went into how he's never had a client who couldn't just put the pets in carriers and put them all in one room, then he questioned why we would adopt feral cats. That was not his job to judge our choice to rescue some cats.

Oh it gets worse, with him not respecting our property. When he was taking up the tile in a bathroom, he put the toilet in our Jacuzzi shower. Did not cover the glass shower doors to protect them from "flying" mastic and tile chips. When we called him on it, the excuse was "I know what that shower is made of, and putting the toilet in there won't hurt it." We said that wasn't the point, the point was you didn't respect our property. Anyway it was excuse after excuse, argument after argument about how we trying to tell him how to do his job.

Well in the end he was pretty pissed off that we expected he followed through on things we discussed and do a proper surface prep, so he quit the job.

We now have a living room with basically a pallet of LVP, boxes of QuietWalk and bundles of base board. We've got another contractor coming in a few days to give us a quote on completing the project.

Hi R H,

Question for you - is your issue spot in a higher traffic area of the basement? Like in a main wailkway? I'm having a similar problem in my basement with newly (partially) installed LVP in our main walkway areas. It's the basement so won't get nearly as much use as upstairs, but it's still where you'd walk every time you go in the basement livingroom/game room. We have Provenza vs. Coretec and it's happening because our subfloor isn't flat in all places, which is slab and on a portion is covered with 70s sheet vinyl. They did smooth the transition spots between slab and vinyl with Ardex, but the rest of the leveling was our task. We did self-leveler in two areas, scraped the floors really well, and used floor patch in areas of the vinyl that were damaged. But alas our slab just isn't flat enough. I'm attaching a video of how much flex our floor has. Is yours this much flex as well? It always makes small crackling noises, and then at times louder cracking sounds. I'm concerned and wondering if I should halt/reverse the install and finish leveling the floor before proceeding. Thank you!

https://www.youtube.com/shorts/KjdpuuJ_VIw

https://youtu.be/wVsa_MER9I0