A Decay Prediction Model to Minimise the Risk of Failure in Timber Balconies

The aim of this paper is the prediction of the life expectancy of timber balconies to minimise their risk of failure. The life expectancy is estimated considering the effects of fungal attacks on the timber structural elements. The prediction of life expectancy of timber components is set up through (i) the analysis of the state of the art, (ii) the definition of risk classes and decision trees, (iii) the prediction of the decay, (iv) the definition of an inspection procedure, and (v) the development of an adaptive monitoring plan. The the state-of-the-art analysis of the construction details that most affect durability allows for defining the risk classes and decision trees that address all the possible scenarios where water can penetrate the construction detail. The decision trees associate one of the risk classes to the detail under analysis providing a straightforward indication about the exposure of the timber structural elements to decay due to fungal attack. The allocation to a risk class allows the evaluation of the main parameters of a decay prediction model based on functions for estimating the decay rate that are available in the literature. The decay predicted and the inspection results provide the input data to the adaptive motoring plan, defining an efficient program of inspections. Case studies were selected to validate the results of the decay prediction on the outcomes of onsite inspections and to provide sample data for setting the monitoring plan.