Treated wood patios – What you need to know…

treated wood patio Patios et Clotures Beaulieu

Treated wood is often preferred for the construction of structures. We would like to provide you with an overview of the chemical composition of treated wood, as well as why Patios et Clôtures Beaulieu only uses treated wood as material for the structure of its client’s patios.

Why are treated wood patios not such a good option?

Wood used for the construction of treated wood patios or other structures, such as wood fences or pergolas, has generally been treated with chemical products through immersion or pressure. These treatments aim at penetrating the wood with chemical products, such as chromated copper arsenate (CCA), pentachlorophenol (PCP), creosote, and more recently alkaline copper quaternary (ACQ). This treatment aims as preserving the life of the wood by protecting it against deterioration due to insects and exposure to the elements. The more efficient method is through pressure, as the conservation product is pushed deeper into the wood. According to a report by the Centre de recherche industrielle du Québec, Profil des produits forestiers, deuxième transformation, bois traité, published in 2003, with this type of treatment, a patio made out of treated wood would last 10-15 years longer than one made out of non-treated wood.

However, in order to eliminate arsenic intoxication risks, treatment with chromated copper arsenate (CCA) was abandoned in 2004 for residential applications, and was replaced by alkaline copper quaternary (ACQ).

Recommended uses for treated wood

For the construction of a wood patio, the use of treated wood should be limited to the structure. In fact, with a treated wood patio, the steps, the floor, the railings and other elements have a tendency to warp and deform with exposure to the sun and the elements. Additionally, a treated wood patio has a shorter lifespan than other types of wood, such as cedar or ipe. In fact, a treated wood patio will last between 10 and 15 years, while a cedar patio (where all the exposed parts are cedar and only the structure made out of treated wood) will last between 20 and 25 years. For a patio made out of ipe wood, it will generally last for more than 50 years.

However, the choice of treated wood is often an economical option and remains, for this reason, a favourite for the construction of a wood patio or fence. If you decide to use treated wood for the exposed parts of your patio, you should choose pine, as it is the most stable treated wood type, with fir coming in second and spruce last. Spruce has the tendency of warping and splitting easily.

References:
http://www.mrn.gouv.qc.ca/publications/forets/entreprises/BoisTraite.pdf
http://www.cwc.ca/index.php/fr/design-with-wood/durability/pressure-treated-wood/about-treated-wood
http://www.bt-securite.ca/acc.htm

About the author

Stephan Beaulieu


“The creation of wooden outdoor spaces for wonderful people is my passion”

Stéphan Beaulieu, president and founder of Patios et Clôtures Beaulieu

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