Moisture buffer potential of wall assemblies incorporating hemp-lime

Abstract

Experiments were carried out according to the NORDTEST protocol to study the moisture buffer value of various wall assemblies incorporating hemp-lime. The following assemblies were tested: a base-case assembly of hemp-lime without any coating, hemp-lime with lime plaster on the upper surface of the sample, hemp-lime with breather membrane, hemp-lime with breather membrane and air layer and plasterboard, hemp-lime with air layer and plaster board. Two tests were carried out with following two air velocities over the buffering surfaces during the moisture uptake cycles: 0.3 m/s and 0.6 m/s. It was observed that, while use of coatings and inner layers reduced the moisture buffer values of the assemblies, yet the reduced values were comparable with the moisture buffer values of some other best performing building materials in their exposed conditions. It was also observed that change of air velocity had higher impact on the moisture buffer values of the exposed hemp-lime and the hemp-lime with lime plaster than on that of the other assemblies.