The presence in timber structures of signs of biological degradation (fungi and insects) is a frequent problem in old buildings and is strongly correlated with the moisture content of the timber resulting from the exposure to the surrounding environment. Reduction of mechanical performance is a typical result of these events with direct impact in the durability of the structure. The beams present in timber roofs and floors are traditionally supported in direct contact with masonry walls. Considering the conditions that may lead to wood decay, moisture monitoring of timber beam-ends near the contact zone between the elements can give a good estimation of the decay risk. This work presents initial results of the spread of moisture inside experimental Scots pine beams in contact with wet masonry, in order to shed some light on one of the factors of this complex phenomenon.