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How to Test Wood Floors for Moisture

Variations in moisture levels may affect wooden floors. Here are some tips for checking the moisture levels in wood floors.
Sonia Nair Jun 30, 2019
Testing the moisture levels is one of the vital tasks, as far as installation of hardwood floor is concerned. This has to be performed before and during the installation process.
Even after installation, moisture levels have to be checked at regular intervals, so that any drastic variation can be controlled. This will prevent the ill-effects that can be sustained by the wood. So, you have to test wood floors for moisture, on a regular basis.

How Does Moisture Affect Hardwood Floors?

Moisture control plays a key role in installation as well as maintenance of wood floors. Shrinkage and swelling of wood depends on the moisture content. As the moisture content drops, the wood starts shrinking and with increase in moisture, the wood swells or expands. So, the wood shrinks during dry environment and expands in wet conditions.
This is applicable for wood floors too. The swelling or shrinking of wood flooring is also affected by factors like, the type of wood species, type of cut, cutting season, weather of the place, etc. The most common effects of moisture on hardwood floors are cracking, cupping or buckling.
So, moisture level testing is very much necessary before, during and after hardwood flooring installation. It has been observed that engineered wooden floors are more resistant to the effects caused by moisture.

Moisture Testing for Hardwood Floors

As mentioned before, testing hardwood floors for moisture starts right before the process of installation. Before the installation, both the wood as well as the subfloors must be checked to find out the moisture levels. It is always advisable to use some kind of moisture barrier, as per the material used in the subfloor.
  • First of all, you have to check the moisture levels of the concrete subfloor with the help of an electronic meter. You may also go for a calcium chloride test or a phenolphthalein test or polyfilm test, for this purpose.
  • In case of wooden subfloors, you may use a probe-type moisture meter or an electronic one. While, the probe-type moisture meter has two pins that have to be inserted into the wood, so as to find out the moisture content, an electronic moisture meter has to be placed over the wood so that it can read the moisture levels.
  • Repeat the testing and note down the moisture levels in different parts of the floor (or different floorboards). Once you are done with the testing, calculate the average of these measurements to find out the moisture level of the subfloor or the hardwood floorboards.
  • You have to calculate the moisture levels on a daily basis, for a stipulated period. Consult a flooring contractor and gain some idea about the admissible moisture levels. If it is too high, then, take measures to reduce the moisture levels.
  • The ideal moisture level for hardwood installation may range from 4 to 18 per cent, on the basis of various factors like, the wood species, the weather of that region, time of the year, etc. As far as wooden subfloors are concerned, the moisture levels must be around 12 per cent or less and the hardwood flooring must have a moisture level not more than 15%.
  • In general, it is said that the difference in moisture levels between the subfloor and the hardwood flooring must not exceed 4 per cent. It will be better to go through the instructions of the manufacturer, with regard to moisture check.
  • Once you get the hardwood, let it get adjusted to the weather conditions of the room. Place them in different parts of the room and measure their moisture levels once a week. You can proceed with the installation, once the moisture levels of the floorboards match with that of the subfloor.
A flooring contractor in your locality will be the best person to provide you with a detailed information about moisture levels and wood floors. You must also make sure to go through the manufacturer's instructions, regarding this aspect.
Once the installation is finished, you must keep a track of the changes in moisture levels of the wood floors, for some time. You must also make sure to keep moisture away from these floors.