The effect of pre-exposure to primary colonising micro-organisms on preservative-treated wood, prior to a basidiomycete decay test, was determined by preconditioning in two soil types. Scots pine EN 113 blocks treated with 3 model systems (a triazole, a copper quaternary compound and a copper boron triazole) were leached according to EN 84 and subjected to 6 weeks and 8 weeks burial in either John Innes no. 2 (a loam-based horticultural compost) or soil from the Simlångsdalen field site in Sweden. The samples were then tested according to the method described in EN 113. Selective isolations were also performed after soil exposure and compared with those from a longer term field trial. Preconditioning lowered the effectiveness of the 2 copper containing preservatives. Some effect of soil pre-exposure could be noted with the triazole but this was limited. The fungal isolations from preconditioned EN 113 blocks and field exposed stakes were a similar mixture of soft rot and mould fungi. Bacteria were commonly isolated from the preconditioned wood. The role of these micro-organisms in the modification of the preservatives is currently being investigated.

Download document (40 kb)
free for the members of IRG. Available if purchased.

Purchase this document