Preliminary results on surface treatments on wood

Abstract

One of the main issues of the international research project SyMBoL - Sustainable Management of Heritage Buildings in a Long-term perspective, is the evaluation of wood mechanical properties. Particularly, pine wood is tested being the main building materials of medieval Norwegian stave churches. Experiments are aimed to assess variations in mechanical properties as a function of environmental conditions. Being wood highly sensitive to RH% changes, pine slices were maintained at 80% RH (4 weeks, 20°C) and successively treated with the materials here discussed on the two main surfaces; afterward, they were left at 30% RH for three weeks. Thus, the loss of water from the samples is supposed to occur only through the lateral surfaces since the chosen sealing materials were selected on the basis of their capability to avoid any penetration of water into the samples. This work represents, indeed, the study carried out to select materials to be applied on the wooden surfaces. Paraloid B72, also coupled with a cellulose sand seal spray, a microcrystalline wax and an epoxy resin were tested. Obtained surfaces were evaluated in term of water repellency (contact angle measurements), uniformity of the surface; penetration of the materials into the wooden structures, colour and water vapor sorption.