What Are The Acceptable Moisture Levels In Wood Flooring?

Did you know that one of the most significant threats to the integrity of timber floors is moisture? Well-maintained hardwood floors can last hundreds of years. Understanding the effects moisture has on timber, as well as acceptable moisture levels in wood flooring, will keep your timber floor looking pristine throughout its lifetime.

How Timber Reacts To Moisture

Wood is a hygroscopic material that contains water, even after it is cut from a tree. It constantly absorbs and releases vapour into the atmosphere. As a result, timber floors naturally expand and contract as the surrounding humidity levels rise and fall. Dimensional stability is a term that describes how much timber will expand and contract from these environmental conditions. In humid environments where the wood will absorb lots of water, it will expand across the grain, which can cause it to swell, warp, and buckle. In contrast, environments with lower humidity will cause wood to warp and crack as the wood loses moisture and shrinks across the grain.

Each type of timber has its own unique equilibrium moisture content (EMC) level, which marks the point at which the timber reaches a level of moisture that matches its surroundings. At this equilibrium moisture content (EMC), wood will naturally stop absorbing or shedding moisture — effectively stopping problems such as swelling, warping, buckling, or cracking in the timber. The ideal moisture for a timber floor will be the moisture content at which the equilibrium moisture content mirrors the installation environment.

Acceptable Moisture Levels In Wood Flooring

Moisture Levels In Different Timber Species

Different species of timber naturally retain more water than others. As a result, it’s important to consider the relative humidity of your home climate when selecting timber to install in your house. Knowing the dimensional stability of the timber species will help you make an informed choice about your ideal timber product and maintenance.

Problems Caused By Moisture In Timber Floorboards

Poor installation or maintenance can lead to moisture-related problems that compromise the integrity of your timber floor. These problems include:


If the moisture levels of your home are too dry for your timber, this can lead to gapping — a problem where the planks in your floor will begin to separate and create thin gaps in between. Floors with large gaps can be unsightly and less comfortable to walk on, and the gaps can trap dust and debris.


If moisture levels are too humid, your timber floor may experience cupping. This happens when the wooden planks become saturated and expand to their maximum capacity, bending the edges upward and creating a U-shape down the centre of the plank. Cupping can create an uneven surface and permanently damage the timber planks.

Timber Installation and Moisture

A conscientious installer will acclimatise your timber floor to the temperature and humidity levels of your home before laying down planks. To achieve this, you may choose to:

  1. Run an air conditioner to achieve a steady temperature in your home
  2. Unpack and stack the timber in this space
  3. Let this air freely circulate around the timber planks prior to installation for four to five days

Ultimately, this allows humidity levels in the timber to equalise with the surrounding environment, minimising expansion and contraction during installation.

Preventing Moisture Issues

To prevent damage to your timber floors after they have been installed, here are some measures you can take.

Care For Your Timber Floors

Avoid letting liquid soak into your timber floors. When spills occur, clean them as quickly as possible without allowing the water to stand. Use fans to speed the drying process. Use a broom or dry mop instead of a wet mop.

Regulate The Indoor Climate

The simplest, most effective way to preserve the integrity of the timber floors is to regulate the temperature and humidity in your home. A humidifier, dehumidifier or air conditioner will help to extend the life of your floors almost indefinitely.

Interested in sanding or staining your timber floor to keep it looking beautiful or repair damage? Brisbanes Finest Floors can help. Get in touch with us today on 0411 220 488.

Brisbanes Finest Floors, with over 20 years of experience in adding wow to any wooden floor, internal or decking.

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Talk to us today and discuss your floor restoration, repairing your deck and new flooring.

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