When winter hits, it also brings with it an aggressive heating cycle. Especially in Colorado, where a quickly moving cold front will drop the relative humidity 10% within hours in a home. The end result is that gaps and cracks develop in wood floors and customers can be surprised.
If you are preparing for any wood flooring project during the winter season, it’s worth to have a quick discussion on wood, coatings, and relative humidity.
Relative humidity is a measure of the amount of moisture in the air as expressed by a percentage. Wood flooring and virtually all wood products prefer environments of approximately 30-50% , which is similar to humans. If you live around Denver, then you know that the arid climate in winter dries our skin, lips, etc… The same thing happens to exposed wood surfaces.
Using a yearly average, most homes around the Denver metro area have an ambient RH of approximately 15-20%. I said that this is an average, which matters because sometimes the number is lower. Several factors contribute to RH in the Colorado region, that I will explain:
Water vapor is suspended in our air up to approximately 50,000 feet. This decrease in water vapor with altitude means that Denver will have approximately 10% less ambient moisture compared to a sea level town like New York City. In relation, if you drove to Aspen or Leadville, the decrease would be even more significant. So how do you combat moisture loss in a wood floor if you want it installed and refinished in a timely manner?
Heating and cooling systems are the most common way to address the moisture levels within a home. Virtually all wood flooring manufacturer’s guidelines require 30% or more RH to warrant the flooring. Yet, in Colorado the building code does not require supplemental humidification of structures.
A humidification system for your home can cost anywhere from $700 installed and upwards of $10,000 depending on the size of your home and the requirements. While this seems like yet another cost, the reality is that in the long term the cost is cheaper than all of the headaches of fixing your gapped and split wood floors.
A second and yet critical HVAC component is the word psychometrics (not your crazy ex). This is the relationship of relative humidity to temperature in a space. As general rule, as air warms it can hold more moisture. To the converse, colder air cannot hold moisture and can cause moisture loss. Because water is a polar molecule, it is attracted to itself like a set of magnets. So, cold air acts like a vacuum for moisture.
It is essential to know that whether you are installing or refinishing a wood floor (or any other wood surface), you should properly condition the environs of the materials. If you install wood flooring at 55 degrees Fahrenheit throughout a remodel, then turn up the heat, it is likely you can cup the floor. We recommend HVAC supplemental moisture for most clients who live in Colorado due to the extreme RH fluctuations and low yearly averages.
The coating to be used on a surface (wood flooring, walls, etc…) need to be in good alignment with their performance environment. Elasticity is a key property of wood finishes that is not always considered by contractors. As you harden a coating, you also decrease it’s flexibility and elasticity. This can be problematic for flooring that is less stable, such as Hickory.
Over time a coating that is less elastic can fracture or stretch (white lines syndrome) along board edges. If you compound this with any upward movement of board edges, you create an exposed edge for the coating. This can result in peeling, flaking, or accelerated wear.
Wood coatings come in many shapes and sizes. If you are working on an interior wood flooring project, then layered urethane coatings are typically the product of choice. These products can greatly affect the movement of moisture though wood, the permeability rating.
I greatly recommend following manufacturer’s recommended guidelines on wood coatings. I have observed cupping in a wood floor that was refinished with a higher build finish system. Likewise, I have witnessed “dry cupping” in floors that where inadequately finished on the surface.
No matter the surface, wood will move with varying conditions of ambient temperature and moisture. In order to best prepare a defense against future adhesions problems (peeling, chipping, and cracking), then the right coating matters.
The Sandhaus is here to provide honest and pragmatic advice to all people. Reach out to us if you have a question or concern about a project.