Karndean Glue Down - dents from furniture, gaps, blotches, telegraphing!

Discussion in 'Vinyl Flooring Q&A' started by JHans, Dec 1, 2017.

  1. Steve Olson

    Steve Olson Hardwood/Laminate Guru Charter Member Senior Member

    Grouting your LVP isn't going to stop it from gapping, its not the answer. After reading this thread, I'm stuck on your statement that your subfloor is only a 1/2" thick? How far apart are your floor joists? if you have movement, it can cause the joints to highlight. You might want to check the MC of the floor joists and subfloor, if you have access to underneath. What was the temp of the subfloor/house at the time of the install? I've seen a swing of 20 degrees cause problems. My guess is possible moisture coming into the framimg/subfloor, is causing the U/L seam problems. The gapping is most likely a temp swing differential. Both of these are something you can control, not the installer. But, this is just one mans opinion.
  2. Chris Mha

    Chris Mha Charter Member Senior Member

    Was the adhesive allowed to dry or was it installed semi wet as it was supposed to on a porous surface? I know Incognito asked earlier but got no answer about trowel notch size.
  3. JHans

    JHans Well-Known Member

    Steve - I agree grouting isn't the answer. Ironically the installer, when first asked about the gaps, suggested we fill them with caulk. And that gaping is normal and acceptable.
    The subfloor has two layers. We gutted the house and left the original 1/2" plywood. We put 1/2" on top of that. Which sat for months to a year, and then put 5/8" over that. So it has two layers of 1/2" subfloor and 5/8" underlayment. The original subfloor was int rough shape.
    The joists are 16" on center.
    I keep coming back to temperature as the cause, but the planks were installed in May and the gaps shows up soon thereafter. There wasn't a temp swing. Then it was fixed in Sept., and the gaps came back literally overnight - no temp swing. Same with humidity. We have a humidistat and that stays constant.
    -I'm not sure where the moisture would come in to cause the seam telegraphing. The seams are all about 4' away from any door, except two that are perpendicular and start at the door.

    Thank you!
  4. JHans

    JHans Well-Known Member

    The adhesive was allowed to sit like 45 min. I remember them checking it to make sure it was "ready" - tacky I think.
    I missed the trowel size question - I do not know the trowel size.
  5. JHans

    JHans Well-Known Member

    Mike I agree - the manufacturer is likely not going to come back with anything helpful. I have no idea what their testing entails.

    From talking with everyone here, and other forums, I have an understanding of the possible scope of the problem - from the first layer of subfloor moisture all the way up to how they laid the glue, and everything in between could be the problem. If it was our fault with the install, I want to know so I don't look like a fool - though some of you already think we do ;). I just don't know what we should have done differently, as both our plywood, fasteners, and install method were approved by two different installers (we got quotes from two places and talked with them about the underlayment). Aside from not placing a seam down a hallway. We didn't think we would ever see that seam again though.

    Am I going to have to get an inspector out to get a for sure answer on what went wrong? I don't want to rip up everything and re-lay something back on a faulty floor. Maybe a different product entirely is the answer?
  6. kylenelson

    kylenelson You'll find me on the floor I Support TFP Senior Member

    I believe karndean likes you to use a 1/16'' notch trowel and set it in semi-wet, which takes a good half hour or more of waiting for the adhesive to flash off, at least in my region of the world. The telegraphing always shows up worse with time. I've seen installs that look near perfect for a couple months then after a year you can see every little thing. People assume that because the product is thick that it will hide imperfections, it won't. The gapping can be from a wide array of variables. Karndean is usually pretty high quality, I doubt it's a manufacturing issue. First step is acclimation, second step is temp control. Sounds like this wasn't an issue. Next is proper adhesive, trowel notch size, and rolling with a steel roller immediately. If these steps are done properly then what's left is moisture, temperature, or manufacturing issue.
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  7. Mike Antonetti

    Mike Antonetti I Support TFP Senior Member

    So, my focus is on Dimensional Stability, have the manufacturers set tolerances for product shrinking? It’s not Rocket Science to know that these products shrink. I think maybe if One wants to protect themselves to know initially what the manufacturer states about product instability, cause after its manufactured to a certain size any changes to me it is called instability. A calibrated micrometer would be needed, 3rd party from receiving product through the stages of its life, installed product and boxed product.
  8. JHans

    JHans Well-Known Member

    I can't comment on trowel size but the adhesive seems appropriate. So does the time left to "dry" before laying planks. They rolled after all was done- so probably like a few hours after the planks were laid.

    The floor patch doesn't seem to be done correctly. Only one coat. Not sanded. We can see "swipes" telegraphed through just as much as the plywood seams.

    A revelation we had today....we can only see the plywood seams that run perpendicularly to the planks. The ones that run with the planks, and with the grain, we can't see. We tried pretty hard to find those using different lights sources, thinking it was just the light, but couldn't. Why would that be?
  9. JHans

    JHans Well-Known Member

    Mike - I'm unsure of what you are saying. I do agree that I expected it to shrink - but honestly then to rebound back with warmer temps/higher humidity. But this has shrunk almost 1/8" in some spots. Everything has shrunk some degree.
  10. JHans

    JHans Well-Known Member

    I am not sure if this is any help to anybody, but we cut out a cross-section of what happened to be a plywood joint. Like I said before we haven't noticed any seams that run parallel to the planks sink. And this one doesn't appear to be. I'm tempted to cut out a cross section of a joint that is sunken to see what it looks like. And just put an extra vent in the room somewhere to cover up the hole.

    Attached Files:

  11. Jim McClain

    Jim McClain Owner/Founder Administrator

    Subfloor is always only the first layer of a flooring system - the layer that is supposed to be mechanically (nails/staples/screws) and chemically (glue) fastened to the joists. Adding a second layer of plywood over that is adding underlayment. Adding a third layer, especially when the existing substrate is already an inch thick, is overkill. You have a 1⅝" thick substrate - that is a lot of wood fiber and layers of glue to trap a lot of moisture vapor. It's easiest path of escape is through the seams between panels. Now add to this the fact that you also have a full, unfinished basement. That is a concrete slab that may not have any moisture barrier under it.

    Unfortunately, you took 3 pages of discussion to tell us about all of that. Doling out important information piecemeal makes it difficult to help you. Some important information you don't even know, like the size of the notches of the trowel the installer used - an installer that already tried to BS you about gaps in the vinyl planks being normal and the same guy who thought filling plywood seams only once was enough and maybe didn't even sand those before or after.

    I can't keep up. I think you need moisture testing on your 3 layers of substrate AND the concrete below it. I'm not sure there is a way to get an accurate test through 1⅝" and 3 layers of the wrong kinds of plywood (the first layer should have been min. ⅝" T&G purpose-made subfloor material). I hope our pro members have the patience to see you through this.
  12. Mike Antonetti

    Mike Antonetti I Support TFP Senior Member

    Here’s an example about the stability. I’ve seen gaps maybe 10% of vinyl I look at. Deleted a good pic of one my wife had me take pictures of for a real estate listing. Failures were always interesting to me to ensure I learned enough to avoid those situations.

    An LVP failure story. Good times!
  13. Incognito

    Incognito No more Mr. Nice Guy! I Support TFP Senior Member

    For the most part vinyl planks gap on the short seam because the adhesive bond to the backing of the material was not strong enough to resist the inherent shrinkage of the material over time and as temperatures change.

    Many manufacturers now want a "wet-lay" or "wet-set" install like the Tandus Centiva planks I'm laying in the Veterans hospital. Calls for a 1/16"x1/16"x1/16" SQUARE NOTCH on a porous susbstrate. 5-10 minutes of flash/gass off/open time then MAXIMUM of 45 minutes of working time-----that includes the 100 lbs roller. So this requires some site specific testing as the open time and working time will fluctuate with temperature, humidity and porosity of the substrate.

    Bottom line-----AFTER rolling with the 100 lbs roller manufacturers require full transfer of the adhesive trowel notch from the floor to the material backing. It's easy to test. After the first section is complete (withing 45 minutes) peel a plank back up to see how much glue sticks to the backing. I'm going to wager------and again, I'll lay 20-1 odds that given your gaps there will not be adequate transfer.

    I see this all the time as the installer wants to "glue it all up" instead of snapping chalk lines and working small sections at a time. In my experience the time difference from an adhesive that sets up tacky and has 7-24 hours working time is a factor of 2-5. In other words it's going to take me 100-400% longer to "wet set" depending on cutting, adhesive type and material being installed. It's a pain in the ass to do planks in small sections. So they glue it all up------MOST OF THE TIME. That's why most of the plank jobs I see are gapped. IMG_2634.JPG
    Coincidentally, I discovered that we could NOT glue up as much a section---working with two installers as shown in the 2nd photo above and get adequate tranfer. After that spread we beefed up the trowel notch, spread smaller sections and got into the glue a little quicker. These are all critical adjustments that professional installers have to understand to be sucessful installers over time.
    Last edited: Dec 3, 2017
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  14. JHans

    JHans Well-Known Member

    Jim - Yes, piecemeal important info is no good. I am not a pro, as all of you know by now, so I gave every bit of info I could think of that would be helpful. And then gave the rest when someone made me think it important. I am having trouble communicating with the retailer/installer. They very seldomly respond to my questions or inquiries. Which is why I am here. Thank you for your patience, and everyone else's.

    Regarding the 3 layers of inappropriate plywood - our house was built in the 70's. The original subfloor was 1/2", not t&g. It was nailed down, no glue. We screwed it down, tore a few sheets up where damaged, and then laid another layer on top - 1/2" cdx not t&g. Then we decided we were going to go with LVP and had to fill the gap that we left in the door frames and jams because we were originally going with hardwood. So we laid 5/8" BCX UL. How do older homes ever have "appropriate" subfloor unless you rip it up completely?

    Moisture - Our humidistat downstairs, directly under the problem areas (and everywhere) reads 50%. We could have the installer test the first layer of subfloor by going into the basement. We could test the middle layer for moisture in the second layer because there are areas of the house that didn't get the 5/8" UL (yet). If we tested each layer, and the basement humidity, would that determine once and for all if it is a moisture issue?
  15. JHans

    JHans Well-Known Member

    This was the method my installer followed:
    Patch seams and fasteners - one coat, no sanding
    Trowel out the glue (do not know trowel size) on 700 square feet. They mentioned 45 minutes, then started laying planks.
    They rolled the planks with a less than 75lb roller (I think it was 60lb but can't confirm)

    When they came pull 3 planks for testing, the first two planks they pulled (in the worst gaping areas) were so easy to pull up. My 4 year old could have pulled them. They did not have much glue transfer - I'd say maybe a few blotches here and there that would amount to 30% of the plank.
    The other area where the pulled planks (the second worst areas for gaping) it took both of them 10 minutes to lift one plank because it was so difficult. I don't remember looking at glue transfer, but the plank pulled up splinters of plywood with it.
  16. Elmer Fudd

    Elmer Fudd Administwative Asst. Charter Member I Support TFP Senior Member

    With regards to your mention of a "humidistat", Is it connected to a water supply, as in an "Aprilaire" or similar". Or is the photo what you are referring to? IMG_5247.JPG
  17. Jon Scanlan

    Jon Scanlan That Kiwi Charter Member I Support TFP Senior Member

    Okay I have done some Googling. Halex is a large well known maker of ply for vinyl flooring in The States
    Reading through their info they even contradict themselves re their product being stable
    1 Why do Halex want the ply to ACCLIMATE on the site for 48 hours before installation? How stable is the ply if one has to do this?

    2 Leave a gap of a minimuim of 1/4" and a maxiumum of 1/2" between the ply and the walls FOR EXPANSION Their words. Stable?
    Halex also suggest to butt the sheets together with no gaps
    3 The big part to me is towards the end under The Note paragraph Quote "That when a Latex adhesive is applied to the underlayment some of the water is absorbed into the wood CAUSING IT TO EXPAND SLIGHTLY. This expansion will force the wet patch out of the joint , forming a bead that can be seen through the vinyl"

    My comments about this last piece is as I mentioned earlier about the moisture/water content of the glue could make the sheets of underlayment dimensionally longer
    I think Halex's words bead is a bit misleading as there were be no bead if sanded SHOP1.jpg SHOP2.jpg
    Halex mention Latex glue but layers have to use acrylic glue on most flooring product these days but as acrylic glue has more water in it than latex glue so there could be more movement sideways of the underlayment In my opinion The bigger the gap between the ply sheets The bigger the problem which you have
    Here is a photo of an underlayment which had no filler with the whole area heaverly sanded to get rid of the bur marks from the staples
    Look between the mats
    The ridges here are caused by lack of blow through ventilation. The vinyl floor is on an underlayment over T&G flooring which is the same level as the footpath outside along with another shop which has a concrete floor so there is no blow through ventilation anywhere near the front of the shop
    Last edited: Dec 3, 2017
  18. JHans

    JHans Well-Known Member

    Just a humidity reader like you have pictured, yes. Sorry for the wrong wording.
  19. JHans

    JHans Well-Known Member

    OK. I'm not sure I quite understand. The plywood joints we left, and the glue applied over the patch of the joints, is absorbing? I read on the document that patch in a 1/4" joint will not dry as fast as surface patch. Obviously that is magnified since we have 5/8" joint depth.
    My problem is in reverse though... I have a "valley", not a bead or ridge. Could thenpatch just simply not be forced all the way down into the 5/8" joint, and thnlen when wet with glue it "sunk into the joint a bit and created the valley?

    Any idea why the seams would only telegraph through the planks when they run perpendicular to the planks? Haven't been able to find any seams telegraphing that are parallel to the planks.
    Last edited: Dec 3, 2017
  20. JHans

    JHans Well-Known Member

    Also, I ordered a wood moisture meter. Will be here Tuesday. Gonna get to the bottom of this.

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