Hello,

I have northen hard maple wood floors that I installed back in late June early July. The installation is a glue down using bostiks best on a concrete slab. The planks are 3/8" solid wood bellawood brand. I didn't have a moisture meter but I did do the test where you take a plastic sheet square and duck tape it to the concrete. You then wait 24-48 hours and note if there is condensation or any indication of moisture. After doing this test, it was dry so I felt confortable with the installation. The wood has been sitting for 6 months in the same room that it was going to be installed. I noticed slight cupping where the wood meets a wall recently. I allowed a gap in the wood close to the wall figuring I was going to install quarter round anyway. There are about 4 planks where the cupping is a little more then I would like. I installed marble thresholds so the wood is flush to those and there is no cupping. I don't think I have a moisture problem with the concrete as the home was built in 1993. I drain the water away from the house and make sure my gutters are clean so the water flows the way it should with out backing up. However, I live in Chesapeake Virginia and we have had an extremely wet and rainy July. August looks like a wet one too! I am thinking that the relative humidity is the problem so I bought a dehumidifier a couple of days ago and noticed an 80% relative humidity! It is down to 59%. But I am wondering if my 45 pint Maytag unit is doing the job or if the humidity is just going down on its own. I have an open floor plan with vaulted ceilings and I am thinking I am asking too much from this unit. The temperature is at 73.5~75 degrees and the humidity goes from 56~70% humidity now. I haven't really noticed any difference in the cupping. I was hoping it would go back. Any ideas? Can you recommend a humidification/dehumidification system if this is the way to go? I am also thinking ahead for the dry winter.

I appologize for the lengthy email.

Steve

Hi Steve,
Personally, I don't like to glue solid floors down, even if the manufacterer says you can( the exception would be parquet). That is what engineered floors are for. Every solid I've seen glued to concrete looks "cupped" to me. Sounds like you're trying to keep your enviroment as close to normal as possible. Any readings of over 50% relative humidity may cause flooring to swell (unless they were acclimated to higher readings). Also, concrete always gives off some moisture. This is what many people do not realize. A healthy slab will continue to generate a small amount of water vapor and the only way to truly measure whether that transmission is within acceptable levels is with a calcium chloride test. This measures the amount a moisture a slab transmits in a 24 hour period ( although the test takes about 72 hrs.) Anyway, bottom line, your "dry" slab isn't really dry and your just guessing that it's moisture transmission levels are acceptable. If one wanted to glue a solid to concrete, I would have at least used a moisture barrier first; just a little insurance. I'm afraid at this point, you're doing about all you can if you do not want to replace that floor.

Thanks Gary,

The floor does look nice overall and I don't think I will be re-installing it. I do wish I knew about putting a moisture barrier because I definitely would of done that. I am not sure how I would do that with the glue down wood? Anyway, I should have purchased engineered wood. Damned if I didn't do my research until after I got the wood. The guy at Lumbar Liquidators made it sound like it was no big deal, wood on concrete.

Is that wall ,where it is cupping ,an outside wall?

Hello,
Yes the wall is an outside wall.

Here is the layout view

I also took some snap shots of the cupping and the general location depicted in the layout diagram:

As can be seen in the photos, I didn't put the quarter round yet but have a small section to use to see the cupping.


This is a picture of the exterior wall where I have my front door

Just inside my door standing in the entry way, the cupping area is up against the wall where the quarter round is

Close up of the cupping (image is a little blurred)

Close up of cupping with the quarter round layed on top flush up against wall

general area of where the cupping is

close up of the cupping

Let me know if you need to see any other photos, I will gladly take more pictures.

Holy crapoli! You have a definite runoff issue. Grab a level and pay attention.

I was thinking it was that. I do drain the water away from the house, but in heavy rains the gutters only do so much as it couldn't take the volume during the tropical storms. I was hoping over time that this would subside and the cupping would reduce.

I have a level, but I am afraid of what needs to be done.

: (

You're floor is definitely cupped. You need to find the source of the moisture and eliminate it. How to do that depends on where the moisture is coming from. Down through a wall, from outside porch slab, under slab.
If caught in time, flooring may go down a little and be acceptable to you. If left for a long period cupped, the wood will develope a "set" and stay cupped, even if you remove moisture source and dry things out. You may have to "patch in"; an ugly job with a direct glue down.

I am going to call someone to search for the source of moisture and possible solution to fix the moisture problem. I was thinking that it was just humidity, but the cupping seems localized to be just humidity.

In looking at the photos, there is cupping off the entry as well. It would appear you have overall cupping, with it worse in some areas. Cupping is caused from moisture imbalance usually originating from below the material. The discolorations on the base may indicated water, or maybe scratched?
This floor may need to be removed.

I appologize if some of the photos make it seem that I have cupping everywhere. However I do not. I took some more close ups with a straight edge to better see what is cupping and what is not.


In this image we see that there is no cupping at all where the wood meets the threshold. However, you can see the crappy bellawood milling of planks on either side.


In this image you can start to see the slight cupping as I move away from the marble threshold and toward the wall. There is a gap between the wall and wood plank of about 3/8" inch to allow the security wire to be routed around the perimeter. However, if I move the straight edge away from the wall the cupping starts to level out.


Now this is the most extreme cupping that I have and it is only on 3 planks in this area. I tell you looking at it head on like this makes it look so bad




However, on this extreme cupping that I showed you in the above photo, we can see that it goes away as you move away from the wall.

I hope this can clear up my issue a bit more.

Steve, Thanks for the great photos! This is an education for all of us on what a cupped for looks like (which after 24 yrs. in the business I've seen plenty of) While you very well may be correct that the problem is localized, it could be the onset of gradual overall cupping. How long has this floor been down? You're doing the right thing to investigate the moisture source first, instead of making repairs and hoping they will work.
Good luck!

Gary,

The floor installation was complete around July 1st 2004. I am nervous and don't really want the cupping to spread. If there is mild cupping in some spots I am ok with that as it is harder to see on the floor. Luckily I chose a light color with a not so glossy finish. However, I want to find the source of moisture and fix the problem. I then want to control the environment with an effective system of humidification in the winter and dehumidification in the summer. Except I don't know what is the best method to do this. I am going to call a home inspector next week to come investigate the moisture issue. It could be several things. I am still happy with the installation as the milling on the bellawood was truely crappy. And when you are down there on the floor putting the stuff down, you are more sensitive to the defects. However when the job was complete the overall results are stunning. I pretty much used the hardwoodinstaller.com site as my guide before the installation. Everything from my simple moisture test, removing overspray off of the concrete floors, to checking the flatness and using the cement and grinding to make sure the floor had a gap of no more then 1/8" over a 10' span. The grinding truely sucked but I didn't want to take short cuts. I only wish that I went to this site BEFORE the purchase of my bellawood. I would of NOT gotten bellawood and I would of NOT gotten solid floors for installation over concrete.

I would like to share with you guys the installation process. Before and after. The only thing you don't get to see is the hard work of grinding checking and more grinding. We layed around 560 sqft of wood!
http://dasp.mem.odu.edu:8080/~shans001/cgi-bin/picture.cgi?dir=WoodFloors

The cupping occured too fast to be anything other than water intrusion, in my opinion. CHuck may have had the best/correct answer;;; leak in wall.
The severe cupping graduating to flat gives you your entry point at the wall. The cupping will increase and grow as the water continues to move.
By your descriptions, diagram (I would love to learn to do that) and photos; you have water intrusion origination at the exterior walls. Water has to sit against the side of the slab for 10 minutes to have intrusion problems. How high is the soil along the exterior wall? The soil should be no higher than the bottom of the interior slab. Is there landscaping directing water toward the house? How long, after a hard rain, does water sit against the side of the slab?
Have fun. You did a great job of describing your problem.
Ray

Agreed from what I have heard and seen.



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