Hello all,

I will be installing hardwood floors in my home in late December. This will be my first time installing hardwood floors and am trying to gather as much information before I “break ground” on this project. I plan on installing 400 ft^2 of ¾” solid, 3 ¼” wide red oak planks. Thank you in advance for your help.

I had a question regarding moisture testing of the flooring and subfloor. Most the information that I have read says that the moisture content of the floors and subfloor (mine is 0.75” plywood) needs to be within some difference (I cannot remember offhand what that difference is (I think around 2%)). But it everything I have read doesn't really say what to do if the difference is out of spec. I think I have read “call a professional” if it isn't within tolerance. I would prefer not to call a professional. What is the procedure when the wood subfloor and the solid hardwood floor is not within the specified moisture content?

Another question I have is what meter should I use to measure the moisture content? I saw some pretty cheap meters on Amazon or local home improvement stores ($20). But then I saw some rather expensive ones ($200). Would a cheaper one be acceptable to use? I don’t want to spend hundreds of dollars if I don’t have to. I did a couple google searches and I didn't see any local tool renters renting a moisture meter.
Maybe I will get chastised for asking this, but is the moisture measurement even required if the acclimation time is long enough? The only reason why I ask is because I am planning on a multi-week acclimation.

In brief:
• What should I do if the floor and subfloor moisture content is not within tolerance?
• Can I get by with a cheap moisture meter?
• Could I skip the measurement all together if I acclimate the wood for multiple weeks?

Where are you located?
Max difference between plywood sub floor and finished flooring is 2% for plank flooring and 4% for strip flooring.
Pin type meter is best. Not easy to push the pins into Red Oak. Probably not worth going cheap. At installation time the flooring should be at the midrange of the annual moisture content for your geographical location....that way it won't expand too much during the high humidity season or shrink too much during the low humidity season. Also, your home's humidity should be kept at 45 - 55 % year round for oak flooring. Acclimation is not determined by time but rather by the humidity in the house. For best results wait until the flooring is at the mc midrange. Humidify or Dehumidify based on the time of year and relative humidity in the house. This process is DIY. Unless you bought from a big box your supplier may be able to provide some advice or contact the flooring manufacturer.

Nature always finds a balance and in wood flooring , this means that moisture will transfer between the flooring ,sub floor and even the air that is in the room below and above .

If your flooring is wetter than your subfloor, your sub floor will gradually absorb or draw in that extra moisture and cause your flooring to shrink and vice versa.

If your flooring is too dry and you know it will swell, you have to install it with spacer rows to allow for expansion without cupping. The other issue is knowing what the seasonal change in your area will bring . Then factor in what type of heating and cooling systems you have in your home . Forced hot air can shrink your wood because it dries out the air.

These are all things that you must develop a feel for or you can get into hot water down the road.

And then there's been a multitude of people that come here because they can't get that subfloor to dry down for many reasons.