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Moisture conditions in timber cladding: field trial data for Sitka spruce

Davies, Ivor; Fairfield, Charles A; Stupart, Alastair; Wilson, Peter


Charles A Fairfield

Peter Wilson


Exposure trials on timber cladding are valuable for informing facade designers. This paper describes a trial using Sitka spruce (Picea sitchensis). Sitka spruce is the only UK-grown timber available in sufficient volume to supply the growing cladding market, but its suitability is unclear. Data indicated that the moisture content range in timber cladding was wider than generally accepted. The minimum of around 10% moisture content appeared to be similar for all details tested. The maximum was influenced by construction detailing but was around 30%. From a theoretical standpoint, the range, and rate, of moisture content fluctuation observed meant that the commonly quoted average value was largely irrelevant. The mode was a more representative statistic; most of the data were skewed towards the wood's fibre saturation point. Sitka spruce is, therefore, at risk of fungal decay and is only suitable as external cladding in the UK if treated with preservative


Davies, I., Fairfield, C. A., Stupart, A., & Wilson, P. (2012). Moisture conditions in timber cladding: field trial data for Sitka spruce. Proceedings of the ICE - Construction Materials, 165, 263-278.

Journal Article Type Article
Publication Date 2012
Deposit Date Apr 17, 2014
Print ISSN 1747-650X
Electronic ISSN 1747-6518
Publisher ICE Publishing
Peer Reviewed Peer Reviewed
Volume 165
Pages 263-278
Keywords Field testing & monitoring; weather; timber structures; Sitka spruce (Picea sitchensis);
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