One of the biggest mistakes made by home handymen and professional installers alike is not allowing wood flooring products including, hardwoods, laminates, engineered hardwood, cork and bamboo materials to acclimate or acclimatize themselves to the room where they are to be installed.
These products all have one thing in common. They all absorb and shed moisture, some more than others and when they absorb moisture they expand and when they shed moisture they shrink.
All of these flooring products may be stored at manufacturers, wholesale and retail distribution centers for weeks and even months in non-climate controlled areas. In many cases they may be stored outdoors, covered by canvas or plastic tarps.
All responsible manufacturers provide very specific instructions on the length of time and methodology to use to acclimate their wood flooring products. Failure to follow these instructions will void any warrantees.
If these flooring materials are not allowed to acclimate to the specific room where they are to be installed prior to installation, within a short period of time, the gaps between the board joints will expand as the wood flooring products shed moisture or if the boards are absorbing moisture they will expand causing the wood to buckle at the joints. Secondarily, boards as they acclimate may cup, twist and/or warp.
When wood flooring products absorb or shed moisture the effect is primarily noticed in the width of the flooring material.
Although you must follow the manufacturer's instructions for acclimating their specific flooring, there are some overall standards;
- The products will take from 48 to 72 hours to acclimate.
Figure 1 - Indoor humidity & temperature gauge
- The room temperature should be between 60° and 75° F (Figure 1).
- Humidity in the room should be between 35% and 55% and should be monitored with a humidity gauge, as shown in Figure 1. These gauges can be purchased for less than $10, and relative to the cost of installing new flooring are a minimal but very sound investment.
- The product must acclimate in the room where it is to be installed. Placing the products in a shed, garage or basement is not an acceptable acclimatization location.
Note: Be extremely wary of any flooring retailer or installer that offers you next day installation of any of the following flooring materials!
Natural & Engineered Wood Flooring Materials:
Although wood is generally considered a solid material it is actually made up of a multitude of individual fibers. These individual fibers have the inherent ability to absorb and shed moisture and they do this continually as humidity levels change where it is currently located. Each hardwood absorbs moisture at different levels, but as a rule of thumb one can say that the saturation level of hardwood fiber is approximately 28%. As humidity levels decrease the fibers shed moisture, at a level below 28% the lack of moisture will cause the hardwoods to shrink. In the same manner as humidity levels increase to a level of twice saturation, 56%, the hardwood will swell.
Hence, the key is to keep the hardwood flooring in an environment whereby the humidity is controlled and maintained between 35% and 55%. By doing this the hardwood flooring material will remain stable and will not swell or shrink.
Note: The acclimation applies to hardwood parquet, boards and slats.
Additional information on hardwood flooring.
Bamboo Flooring Materials:
Bamboo is not a hardwood it is a grass, but it has the same fiber characteristics and hence responds to humidity in the same manner of hardwood flooring. To ensure that the bamboo flooring does not swell or shrink after installation it must be acclimatized to the room and a humidity level of 35% to 55% should be maintained throughout all seasons.
Additional information on bamboo flooring.
Laminate Flooring Materials:
Laminate flooring is created by gluing a picture of a floor, ceramic, stone or wood to a core material. In most cases the core material is a wood derivative made up of sawdust and a bonding agent such as epoxy. The sawdust within the core material will swell and shrink relative to the humidity levels in the room and hence, the product must be acclimatized prior to installation and the room's humidity levels must be maintained in the same manner as bamboo or hardwood - 35% to 55%.
Additional information on laminate flooring.
Cork flooring Material:
Cork is the bark of a species of oak tree. Yet cork does not have the same fiber makeup of hardwoods or bamboo and hence reacts somewhat differently to different levels of room humidity. However, it still does shrink and swell as humidity levels rise and fall and hence it must be acclimatized to the room it is to be installed in and the humidity levels in that room must be controlled.
Follow the manufacturer's specific information.
Additional information on cork flooring.
Controlling Indoor Humidity Levels:
Indoor humidity levels should be controlled not only to protect your wood flooring, but for the overall health of you and your family. Indoor humidity levels can be adjusted by using humidifiers to raise humidity, dehumidifiers to lower humidity and air conditioners.
Note: Sub-floor materials, such as plywoods, should also be acclimatized.