How Does Temperature Affect Wood?
A natural, eco-friendly building material, wood interacts with its environment. Generally, this interaction has no negative impact on its function, however it is important those who want to use wood understand the way it is affected by climactic conditions. Taking into account the properties of wood and how temperature change, sunlight, and moisture might affect it is crucial to the longevity of your project, but can be difficult to figure out alone.
NORclad is a specialist timber cladding supplier and manufacturer. With 40 years’ experience in the industry, we’ve helped building projects all over the UK discover the environmental benefits of timber, and its durability too. Combining expert advice with plenty of passion, we can help you make the most of your materials – now and long into the future!
In this article, we explain the effect of temperature and other climactic conditions on wood and suggest how to minimise it.
How Does Temperature Affect Wood?
Wood is a highly durable building material. This, alongside its unique aesthetic, is why wood has long been a popular choice for architects. Despite this, it is a natural product and certain climactic conditions can have an effect on its form and appearance.
Overall, wood tends to be resistant to temperature changes. This is because it has a low thermal conductivity compared to other building materials like metals, marble, glass, and concrete. This conductivity is greater in the axial direction, and tends to increase with density and moisture content. That means the best species for insulating your building will be light and dry.
Timber Species Guide >
Timber even has good credentials when it comes to resisting extremely high temperatures. When wood is exposed to fire, a layer of char forms on the surface, shielding the rest from the flames. This means a structure made of wood can maintain its integrity for a lot longer than other building materials like steel. And when treated with fire protection coatings, this resistance can be enhanced, making it the ideal choice for public and private applications.
Temperature can affect wood indirectly as a result of its influence on humidity. Warm air tends to carry more water vapour because the particles have more energy and are less likely to condense. However, the most important factor is how much water is available nearby. So, a better question to ask is: how does moisture affect wood?
See more: Wood Protection – How to Protect Wood/Timber from the Elements >
How Does Moisture Affect Wood?
Wood is hygroscopic, meaning it absorbs moisture from the air. This is because wood always wants to be in equilibrium with its environment, and will release or take in moisture to find that perfect balance. When wood releases moisture due to lower humidity in the surrounding air, it will contract. When wood takes in moisture due to higher humidity, it will expand. Both of these things can cause cracking, warping, and buckling if not properly accounted for.
Related: How Timber Cladding Weathers – All You Need to Know
How Does Sunlight Affect Wood?
High temperatures tend to mean high levels of UV light, which can affect the surface appearance of timber. Photochemical degradation can occur if wood is exposed to high levels of UV light, making cladding turn a silvery grey colour – which can be highly attractive! This is caused by solar radiation depolymerising lignin in the wood – a key compound making up the support tissue of many plants and especially important to the structure of cell walls. Once depolymerised, any subsequent rain will cause the degraded fragments to leach out of the wood and alter the exterior appearance of the cladding.
Read next: Timber Cladding Maintenance – Tips and Advice
How to Protect Wood from Moisture
There are a few important steps to take to ensure your timber isn’t adversely affected by the moisture content of the surrounding air. No one wants to see their design and vision for their cladding impacted by improper installation. Below, we suggest some great ways to avoid this.
Choose the Right Species
If a uniform, unchanging aesthetic is vital to your project, you’ll need to choose a species that has high dimensional stability. Some of the most weather resistant species include Canadian Western Red Cedar and Abodo.
Ahead of installing your timber cladding, it’s important to store it correctly to prevent degradation. Keep the timber away from direct UV light, rain, snow, ice, and any other elements, and make sure it is kept off the ground with plenty of air circulation.
Read next: How Long Does Timber Cladding Last?
It is always wise to allow the wood time on the project site to acclimatise. As we have discussed, wood always wants to be in equilibrium with its environment. The inevitable change in conditions from manufacturer site to project site will mean it needs to adjust its moisture content either by releasing or absorbing moisture.
This process is difficult to put an exact timeline against, therefore it is always good practice to measure product prior to installing, comparing these finished dimensions to when the product was freshly machined. If you’re unsure how long to leave yours, contact us today and we’ll be happy to advise.
Install to Account for Changes
Both treated, and untreated cladding may expand or shrink slightly in situ, so it’s important to install with this in mind and incorporate space for this natural process to occur without it affecting your build. For more information about installing timber cladding with wood’s innate properties in mind, visit our download centre.
See more: How to Install Timber Cladding
Choose Treated Timber
You may want to opt for treated timber to minimise the changes you see as a result of weathering. AccoyaÒ or acetylated timber is modified using lead-edge patented technology to ensure greater stability and lower maintenance. ADOBO achieves similar results by thermally modifying the timber. This, alongside patented vertical grain construction, alters the chemical and physical properties of the timber to reduce moisture penetration and allow the use of wider boards.
Accoya Cladding – Features, Benefits & Uses of Modified Wood >
Specialist Timber Cladding Supplier
NORclad have been manufacturing high quality timber cladding products for over 40 years. Our team are highly knowledgeable and will be on hand to advise you from initial enquiry right through to installation. We’ve supplied timber for a range of exciting projects across the UK, and yours could be next!
Talk to us today and we’ll show you what timber can do for your build.
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Read more: Outdoor Timber Cladding – Everything You Need to Know