Analysis for Wood Decay within Building Envelops Considering Moisture Production by Biochemical Reactions

In this study, a durability assessment model forbuilding envelopes design based onhygrothesmal and wood rot decay analysis ispresented. The durability assessment model canquantitatively predict hygrothermal conditionswithin the building envelopes, and progress ofwood rot decay of timber frame under variableconditions. The followings are characteristicsof the durability assessment models in thisstudy. One is that development of wood rotdecay is represented by a differential equationwith a variable of mass loss; the other is thatmoisture production by wood rot decay isadded into moisture balance equations. Hence,the model can assess long term performanceregarding both durability and drying potentialfor building envelopes. In this paper, sensitiveanalyses were implemented to better understandimpact of the moisture production on the decayprocess. Additionally, progress of the wood rotdecay within an external wooden wall isdemonstrated.