Western Red Cedar’s natural durability often makes this wood species first choice for external cladding, and this was no different for Leven Valley Primary School.
As part of a refurbishment programme the school wanted to update its hall, which was originally constructed as a temporary building in 1929. The hall desperately needed some attention to bring it up to modern standards as the windows were all single pane glass, and there was no insulation in the timber frame, making it hot in the summer and cold in the winter.
Rather than demolish the building and start from scratch, the school decided to work with the existing frame and update the materials to make the building fit for use.
Leven Valley Primary School is located in the Lake District National Park, surrounded by beautiful woodland so the building had to use natural materials that blended into the landscape.
The main concern for the school was the lack of insulation in the building. New double-glazed windows and sheep's wool were used to insulate the building. An additional layer of insulation came from the Western Red Cedar 'board-on-board' style cladding. Wood in general has low thermal conductivity, but the low density of cedar makes it one of the best thermal insulators of any wood species.
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Western Red Cedar was chosen as the cladding material, not only because of its beautiful natural appearance, but also its proven ability to perform in damp environments. As the Lake District experiences more rainfall than any other part of England, this was an important consideration.
Leven Valley Primary School wanted to let the cedar age naturally to a silver grey but understood the importance of protecting the wood from moisture. It was decided to protect the cedar cladding with Sansin Wood Sealer which was factory applied by Silva Timber prior to delivery.
Sansin Wood Sealer is a water-borne penetrating sealer with very low volatile organic compounds (VOCs) that works by repelling water whilst allowing the wood to breathe. Wood protected with Sansin Wood Sealer doesn’t hold excess moisture, so it is far less prone to water staining, mould and algae growth and turning black. As it’s invisible the wood looks totally natural and, because it contains no pigments, Wood Sealer allows the wood to weather gradually to a consistent silver grey colour.
Leven Valley Primary School focused on sourcing natural, environmentally friendly materials for the build as they felt this would create a better learning environment and highlight the importance of sustainability. Timber is the most environmentally friendly building material as it is a carbon sink and it's renewable. The Western Red Cedar used in this project was PEFC certified showing it was sourced from a responsibly managed forest.
Even the product used to protect the wood is an environmentally friendly choice. Sansin Wood Sealer contains only 10 grams per litre of VOCs (the EU regulatory limit is 130 grams per litre), making it one of the most eco-friendly wood protection products on the market. VOCs contribute to atmospheric pollution, so using products like this helps create a healthier environment.
An inspection 12 months after installation showed that the Western Red Cedar cladding and Sansin Wood Sealer were performing perfectly together. In an area with high rainfall and large trees surrounding the building creating a damp environment, there were no water stains, black marks or mould growth and the cladding is mellowing steadily to a pleasing silver grey colour.
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