A study on moisture movement within traditional and contemporary building materials

Abstract

This study is an investigation into water vapour and liquid moisture movement in selected traditional and contemporary materials and how the hygric properties of these materials can to be put to advantage to improve the indoor air quality of a space. The response to changes in air relative humidity was studied for materials and systems which are typical building components of the Maltese built environment. This was carried out by following the methodology undertaken by foreign laboratories in Northern European countries which devised the NordTest protocol of attributing a 'Moisture Buffer Value' to materials, in order to classify their performance with respect to the amount and rate of sorption at cyclic RH variations. The hygric properties related to density, water vapour permeability, porosity, water absorption by capillarity and hygroscopic sorption were also investigated for the same materials and systems, in parallel with the NordTest protocol. This enabled the comparison of theoretically-derived and practical results on the ability of materials to 'regulate' indoor relative humidity.