Everyone knows wood floors don't get along with moisture right?
The bigger question is just how much moisture does it take to adversely interact with wood floors? The answer is: not much! (some species such as mesquite and bamboo are more resistant to moisture than others)
Wood ishygroscopic, which means it is capable of “absorbing or attracting moisture from the air” or “readily absorbing moisture, as from the atmosphere”. This means when wood absorbs or releases moisture, it will change in size. Some degree of movement is normal throughout the change in seasons.
To minimize this effect on your wood floors, the relative humidity in your home should remain somewhere between 30%-60% year round. Temps should remain between 68-72 degrees, give or take. Some HVAC thermostats have a built in hygrometer, to measure relative humidity. If yours doesn't, you can buy one with a minimal investment at your local electronics store, or on the internet. This simple instrument can help protect your wood flooring investment!
This is a good reason to leave your HVAC system ON while you're on vacation.
There are a lot of variables within a home that can cause moisture issues with wood flooring. Here are the most common issues we see:
Below grade homes - solid wood floors are not suitable for this application, but engineered wood flooring generally is.
Inadequate ventilation in the crawl space of pier and beam homes
Leaks at an exterior door or fireplaces
Excess pressure washing on an exterior wall adjacent to wood flooring. (if the water is able to reach the base plate and migrate through or beneath it, then moisture can get to your wood flooring or subfloor)
Seasonal use of HVAC systems. If the RH drops below 30%, it can cause cupping and gapping. If the RH rises above 60% it can cause expansion and buckling. (if you only use your home during part of the year, you should consider running the HVAC system when you're not there - it can save your wood floor!)
Inadequate weep holes in your exterior masonry. Moisture builds up behind masonry and if it doesn't have enough proper weep holes to escape from, it can migrate to the interior of your home.
Improper brick ledge. A brick ledge acts as a sort of "dam" to help keep moisture from migrating inside the home. It works in conjuction with weep holes to accomplish this.
Installation of wood flooring before conditions are acceptable. The moisture content of wood flooring needs to be between 6%-9% and somewhere within 2%-4% of the subfloor or concrete moisture content, as well as the relative humidity between 30%-60% prior to installation.
If you notice any excess buckling, cupping, or gapping in your wood floors, you should contact your local hardwood flooring expert! Proper use of a moisture meter and experience can help determine the source of the issue. A professional can determine a plan of action to solve your moisture problems.