Leaks represent a very important hazard for the buildings and they can affect all sorts of building materials and specially wood due to its hygroscopic properties. Excessive moisture content can affect in a negative way building processes such as the installation of wooden floors or the use of wood as a structural material. Moisture meters can provide prompt and non-destructive determination of wood moisture, and as such are among the most useful tools available to wood products manufacturers and scientists. However, a continuous monitoring system is needed in order to avoid excessive moisture content which can damage wooden floors as well as structural wood. Data and procedures are presented in order to develop a suitable monitoring tool based on wireless sensor networks to provide an electronic tool of active security both for the installation of wooden floors and for the proper maintenance of existent buildings which have a timber structure.