In most areas of the U.S., it is just not possible to keep indoor relative humidity levels where they need to be for wood flooring without a whole home humidifier.
With the temperatures dropping the correlating relative humidity in the atmosphere also drops. You will likely have noticed this when going outside during the cold weather with your lips and mucous membrane drying out.
And just because there may be lots of snow and ice on the ground, the air itself can still be very dry or at a very low level of RH. The colder the winter weather gets, the more families turn up the heat which only accelerates the drying process.
Indoor conditions often are drier than the Sahara desert.
This is why it is important for wood floor owners to get a humidifier for their homes:
When the RH outside drops to an average % below 35%, this should trigger an autonomous response to turn on the humidifier(s). Otherwise you might see substantial gaps, shrinkage, cracks and cupping.
Many wood floor owners don’t realize the importance of having a humidifier. And others that do have in-home humidification have not been properly educated on how and when to operate these.
An example of this can be found in one home inspection I recently did in Oklahoma City. When I asked if the home had humidification, the homeowners assured me it did. When we checked the setting on the unit, it was set to only 35% when the dial had a range up to 65%.
Since the RH in the home was recorded at under 30% there was no way in the world that the humidifier would ever put enough moisture back into the home to raise the RH to within normal range of between 35%-65%.
Download our RH guide to learn more about how your floors are affected by cold weather.
Your Winter RH Guide
Monitor RH with a humidifier and hygrometer
These devices are not very expensive, and will protect your investment in wood flooring while making your home more comfortable to live in.
Aprilaire has become one of the best brands for whole home humidification. We have one installed in our offices in Oklahoma City, and it works great. Additionally, you may want to supplement this process for when the heat is not on with a free standing unit. Several brands we have used were purchased from the big box stores. Brands like Idylis and Honeywell work well for areas where the floor shows additional gapping or dry cupping.
In addition to a humidifier, a hygrometer is recommended as a second way to measure the moisture. This way you can ensure that your humidifier is actually keeping your RH levels where you want them; sometimes humidifiers can be unreliable.
Hygrometers come in all shapes and sizes. They are readily available from stores like Home Depot, Walmart, and Lowe’s. The best brands are those from manufacturers of electronic sensors like Delmhorst, Wagner Meters, Lignomat, and Acurite.
There are several types of humidifiers all requiring different kinds of maintenance ranging from paper filters, nylon or plastic mesh filter, to electrolysis (filterless). Each of these require different methods to keep them running, so you’ll need to contact the manufacturer for cleaning and maintenance guidelines.
We have a unit that requires 4 paper filters that we change periodically after running through 150-200 gallons of water. This will vary with your environment and the amount of dust and dirt the filters are picking up. A rule of thumb is that when the filters become discolored and hard with mineral deposit, they need to be changed out.
Tim Fowler has been a member of the NWFA since 2006 and a member of the MFMA since 2012. He’s been involved in sport sales for the past 8 years and initiated the sports sales program for The Master’s Craft 3 years ago with a service area ranging from Nebraska to South Texas. No doubt he enjoys both the maple court as well as his home town team OKC Thunder.