Wood floor popping

[Nick commiato]

I have a problem and am looking for some help or advice to figure out a solution. I had bamboo flooring in my son’s nursery, it was installed by the previous home owner and had been there for at least 10 years. We decided to put carpet in the room and Home Depot told me I didn’t need to rip up the wood flooring. (The flooring was in perfect condition prior to carpet installation). So we put carpet down with a foam underlay. About 5 months after carpet went down we noticed you could feel the wood planks starting to pop up under the carpet. So I just pulled the carpet up and the wood flooring had a darker tent to it, particularly in one area but over all just looked like a worse condition than it did before the carpet was laid and planks were starting to buckle. As I pull the wood up you could tell there was a slight amount of moisture. No standing water or anything but you could tell it was damp, it never got wet enough to get the carpet damn or even the foam underlay really. However, I cannot figure out what caused the moisture. The foundation is in perfect shape, no cracks or anything, there are no bathrooms or water pipes in the vicinity of the room, the dirt on the outside of the wall is graded away from the house properly and there is not standing water or anything but intrusion into weep holes.

What is causing this moisture?

The only thing I can think of (and I don’t even know if this is a real thing) is that the foundation wasn’t sealed great in that room and just has a little moisture seeping through and when it was the wood floors it was able to breathe and evaporate but when the carpet went down it sealed it up and trapped whatever slight amount of moisture might have been coming through. Is this even a thing??

Please help me.

 

[robinbanks]

Sounds to me like you're right, and the underlay plus carpet has created enough of a barrier to allow the wood to remain/gain moisture and swell

You could ditch the carpet and go back to wood (in a nursery that would be my preference for ease of cleaning!), or take the wood up and have a good look at what is happening below

 

[Nick commiato]

We did pull the wood floors up, no cracks or any evidence of major water, just a very light amount of dampness. My wife is adamant about having carpet in there.

The house was built in the 60s so I’m unsure of whether a vapor barrier was used for the foundation or not. As a side note, we did carpet in the office at the same time and it was a stained concrete floor, no issues in there with moisture at all. So what would be my options or an appropriate solution for the nursery in order to lay the carpet back down? Is there a sealant or vapor barrier I can put on top of the slab under the carpet that won’t cause me more/worse issues later down the line? I’ve attached pictures of what the slab looks like under the worst areas of the wood flooring.
Thank you for any help or advice!