Hello all,

Looking to get some information:

I am currently installing 3/4 inch pre-finished hardwood oak floors. They are being put over 3/4 inch tongue & groove plywood. I put wax paper between the hardwood & plywood. Plywood is nailed & screwed to the joists, and the plywood made 0 sounds when walking on them.

The wood has been siting in the home for around 2 days before it was installed (as per manufacturer guidance). The humidity has been a bit higher than what the manufacturer's guidance (they say between 35 - 45) but due to the hot spell, humidity in my area has resulted in the house being around 60%. I purchased a de-humidifier to help (the house is only around 900 square feet).

The newly installed floor in the hallway looks great. No cupping, no waves, straight & solid, but I realized that each day I walk into the home, that there seems to be a crack / pop when I first step on the floor. The noise will happen once, and then I am unable to get the floor to make any sort of sound afterwards. I could be there for 3 hours and will still hear zero noise. It is only when I walk in for the first time after a day or so does it make this noise.

I read some stuff saying that new hardwood floors may do this after installation, but I am not convinced. I have not continued to installation just yet, as I want the humidity to lower before continuing.

I only installed around 150 square feet so far.

Should I worry about the floors making this noise? Will lowering the humidity & temperature maybe correct this problem? As of right now, humidity is not controlled, nor is there A/C in the home.

Hardwood was nailed with U-shaped nails going into the plywood (I believe they were over 1.5 inch thick).

Any advice would be greatly appreciated.

Thanks in advance,
Massimo

You may have seasonal popping which will go away after the flooring settles in.

It sounds like a humidity issue - be very careful with acclimation in the high humidity season. As you state, the house is not climate controlled, meaning the outside RH and the inside RH will be similar, and at this time of year, TOO HIGH. 60% RH is high - worse, now you've acclimated the material to this high humidity in the space, meaning the wood is fat going in and will contract once the climate control is in place and RH goes down to normal.

What this means is, you will see gaps between boards as they start to shrink. If you installed at 60%RH and the wood has a high MC, when you turn the heat on for the winter season, don't be surprised to see gaps as big as 1/4 inch appear between boards. This extra space also creates movement and noise at the T+G.

To compound the issue, it seems like you didn't complete the install all at once - meaning you can't really fix the issue with dehumidifiers without affecting the 150 sqft you already installed (in other words, lets say you managed to dehumidify over a couple days and got the RH down to the recommended level of 45%, the newly installed material will go in nice and tight, but gaps will have already appeared in the installed section). This might not be so bad as only 150 sqft may have to be redone, instead of the whole install.

My advice, take up the 150 and do it again after closing up the house, turning on the AC and getting RH to 45-50%. Acclimate the material to these conditions and KEEP the same conditions after the install is complete. Take MC and RH readings daily leading up to the install to make sure the site and wood is in the correct state. Without MC and RH readings, you'll never get a warranty out of the manufacturer.