I just started a floating (click lock, engineered hardwood with 7 ply) install over tile. After a long 12 hour day, I'm about 1/3 done.

I checked the flatness carefully and fell within manufacturer guidelines (3/16" variance over 10 feet). It looked pretty good, but I just realized I have about 3 very small subtle mushy spots. I'm using Roberts 3 in 1 which I think is a high quality underlayment.??

I realize this is a product of the tile subfloor not being even. It's very subtle and I can only notice if if I pay close attention. I can live with it but my question is... Will these spots get worse over time (get more mushy)? Could more spots like this arise in other locations?

Also I live in San Diego where weather & humidity are pretty consistent.

Thanks in advance.

You probably just missed a couple high corners on some tiles. How are you checking it? You can miss them using a string. I like using a metal straight edge more. Hard to say what you think is subtle. There can easily be a couple spots like that in any installation and the floor should handle it. But not many or large areas.

It's very possible that your substrate is within spec, and those soft spots are a result of the material. A certain number of the planks will not be flat coming out of the box. This can create what your talking about, and will flatten out in short time.

Are you suggesting an unbalanced board or plank, will straighten out? Just asking, not starting a heated discussion.

It sounds to me like high tiles that are creating a ridge. If so these will not lay down. The specs mean a subtle slope not ridges.

Man, I must come accross touchy, I think it's Floorguy's hit and run posts, or maybe when Ray jumped back on here . Selva, I dont recall installing most hardwoods where there wasn't at least one or a few boards within a box that weren't flat, well maybe Mirage, and a few others.
Infact first installing floaters....I ran accross a few that had me concerned. Here I knew I was within spec, I was getting "soft spots" and slight "creaking". I called the tech dept. of the manufacturers and they would assure me the floor would relax and lay down flat. Low and behold they were right. It seems that a soft spot will flatten out in a faster timeframe in traffic areas. I've had a few frustrations along edges,( no traffic), and was more aware of choosing planks. I've even run accross boxes that spring open Ofcoarse, of little concern with gluedown or naildown.

As per my phone conversation with the OP.....We talked about how meticulous he was with substrate spec," especially over the ceramic tile", still had the "mushy spots", and brought up creaking. After our conversation...I'm led to believe He's run accross this "out of the box", "plank flatness" issue.


When I first ran accross this issue, it had me very concerned. I took a bowed 7 ply plank and laid it flat on my worbench. In 2 days I pulled the weight off the plank, and it stayed flat. While not a conclusive test, and certainly different conditions, the plank did flatten out, and I felt a little more at ease. I was then able to weight down a few soft edges,(against the wall, no traffic) on the job, it worked like a charm.

I have a 3.25 engineered on the rail of my back porch, sometimes it is "engineered cupped" and sometimes, flat.

So, I have seen some engineered cupped out of the cartons, with some flat in the same carton. So, my reasoning says some may have had a moisture imbalanced at time of pressing, maybe. Can't really know, only know, it is there.

Jess a-asking.

Did he call you as well Howard? We might have toi start charging by the minute like lawyers.









Hmmmm, engineered cupped. Must be a wood science term. heh heh Maybe he means bowed. I've heard of that "imbalance" in layers as it's pressed. But there are other forces at work here, not just the old worn out imbalanced moisture content in layers.

Well, here's the thing. Like Howard says about them flattening out, I've weighted them down as well when using really bowed planks in closets. Those dern long planks are always the worst, good seven footers are almost always bowed a tad anyways.....is that normal,,,,,hmmm

Oh well could be the wood drying as the rh is not high enough in the room and it starts tweaking. So if my rh is at the manufacturers lowest number say 30% for installation requirements....thats a good 20 to 25% off from the high which is usually around 55%. So, even though that woods moisture content is even throughout the plys and 6 to 9% mc it can start warping right outa the box. If it's down to say 7 to 15% which is normal out here you can watch it"engineer cup" right before yer eyes,,, his eyes!!!

Funniest thing is about them planks coming outa the box as some are and are not bowed, yet cut from the very same panel during manufacturing hmmmm how can that happen, when one is bowed, the one next to it not,,,,amazing and almost illogical and unscientific!!


So what about that glue, he askes hisself:

Yes...I was a little thrown off with that "engineered cupped" phrase. I'm glad you cleared that up,( where it came from). I WAS referring to "bowed", out of the box.

Yes, We might have to start thinking of the "Hardwood Flooring Talk message board hotline", I think we can set it up with the phone company, and charge per minute

Well I knew you were, he is just trying to throw ya. I bet they are trying to figure out where that quote I posted came from. heh heh

I await an answer to the question (with baited beer breath) about moisture imbalance in plys making some planks bow when the next plank outa the box is not and most likely cut from the same panel, even directly next to it. Buuuurrrrrp!





Yea but then Ken's gonna want a piece of that action. lol

Let's get it together! There's plenty of room, and Ken is the marketing guru


On the other note.....One of my theories is "stacking". When planks are stacked in the carton,( even cut from the same panel), there may be an ever so slight,( hardly detectable), moisture content difference. Then all planks enclosed in the box and this is magnified, and effecting one another. All it takes is one plank, like one person with the flu bug, to leave their mark. Maybe off the wall and one of my many worthless theories I'm hoping to be corrected by the "experts".

Your theory seems somewhat sound but I find it difficult to believe there could be one plank cut from the same panel that would exhibit such a higher MC that could effect the rest of the box. Even if the adhesive was the culprit. But, how could you tell anyhow? If it were a ply that had a higher MC it would effect many planks as the sheets cover a large area of the panels. There can be multiple sheets of ply in one layer though.So in effect the theory of a ply with a higher MC effecting one single plank out of one box seems quite illogical to me.

Did I use those terms correctly? lol

http://www.reference.com/motif/Health/w ... sus-affect

I always have problems with those words. Thank you, now I know Effect is the End result, and not when something is in the process of being Affected

Yea, I know that theory has holes in it. Better study up on my "wood science", for a future attack All kidding aside...For myself.

Darn good question....Why are a few planks bowed, in the same box, with surrounding planks cut from the same panel ?

There's more than one way to make an engineered floor though.

http://www.youtube.com/watch?v=BiFsacuD ... re=related

http://www.youtube.com/watch?v=t7uYXirZqUg