The effect of different test methods on durability classification on modified wood

Abstract

In order to encourage increased use of wood more empirical data on the performance of wood products are needed from different exposure situations and geographical locations. In the current study modified Scots pine sapwood materials aimed treated for above ground use were compared using: 1) two different laboratory decay tests at three different climates, 2) four different laboratory moisture tests, and 3) two different field trials. The aim of the study was to investigate the effect of temperature and moisture on modified wood material performance in laboratory decay trials and to compare different durability classification methods. Lowering the temperature did slow down the decay rate, but did not make much difference in the durability ranking of the materials. The moisture behaviour of the materials in this test could not alone explain the decay resistance. The durability classification varied between the tests, confirming that the durability classification of a material, and the ranking between materials, is not a fixed value that can be based on one single test. In order to predict service life in future studies the authors recommend to combine decay and moisture data.