Towards modelling of decay risk of wooden materials

Abstract

An empirical model for wood decay development which can be incorporated into a hygrothermal model of building physics is presented. The model is applied to the ERA-40 reanalysis data, based on six-hour weather observations in Europe, to estimate wood decay in different parts of Europe. These studies provide new tools for evaluating the durability and service life of wooden products and a preliminary European wood decay risk level map. The effects of the projected climate change on wood decay may also be considered by this methodology.

The minimum moisture threshold for wood decay by basidiomycetes revisited. A review and modified pile experiments with Norway spruce and European beech decayed by Coniophora puteana and Trametes versicolor

“…Wood moisture content (MC) and temperature are recognized as key environmental variables to quantify the risk of fungal decay and to predict the service lives of wooden structures (Bavendamm and Reichelt 1938;Griffin 1977;Brischke et al 2006a,b;Viitanen et al 2010;Naumann et al 2012;Thybring 2013;Zelinka et al 2015). Many different models were developed to describe the effects of temperature, relative humidity (RH), and in some cases also rain events on decay (Brischke and Thelandersson 2014), but among all parameter the minimum moisture threshold (MMThr) value is the most important one, below which the decay cannot be initiated.…”

“…MMThr and other physiological requirements of decay fungi are usually tested in laboratory experiments (Viitanen 1997;Viitanen et al 2010), and also in the field (Scheffer 1971;Augusta 2007; Van den Bulcke et al 2009;Meyer-Veltrup et al 2017). It is agreed that available free water in the cell walls is critical, but not that in the cell lumens Stienen et al 2014).…”

Moisture and Bio-Deterioration Risk of Building Materials and Structures

“…. a) Modelled mass loss (in %) of small pieces of pine wood that are protected from the rain or b) exposed to rain in 10 years in Europe (from [Viitanen et al 2010b[Viitanen et al , 2011b The risk of decay activity in different part of Europe can be evaluated on the map. If we evaluate the decay activity rate in Helsinki to be 1, then the decay risk in north-western part of Portugal and in West Ireland is 2 times and in Atlantic part of France and Belgium it will be between 2 and 2.5 times higher than that in Helsinki.…”

Moisture and Bio-deterioration Risk of Building Materials and Structures

“…The empirical wood decay model was run using the ERA-40 data for air temperature, humidity and precipitation at 6 hour intervals (Viitanen et al 2010b). ERA-40 is a massive data archive produced by the European Centre of Medium-Range Weather Forecasts (ECMWF).…”

“…. a) Modelled mass loss (in %) of small pieces of pine wood that are protected from the rain or b) exposed to rain in 10 years in Europe (from [Viitanen et al 2010b[Viitanen et al , 2011b The risk of decay activity in different part of Europe can be evaluated on the map. If we evaluate the decay activity rate in Helsinki to be 1, then the decay risk in north-western part of Portugal and in West Ireland is 2 times and in Atlantic part of France and Belgium it will www.intechopen.com be between 2 and 2.5 times higher than that in Helsinki.…”