Lightweight Bathrooms with Increased Durability

In Denmark, the use of lightweight wet rooms has been common for the past 30 years. Over the years a lot of experience regarding robustness and service life has been gained from investigations in the laboratory as well as from practice. Normally, lightweight wet rooms are considered to be more vulnerable and less robust than the old type of heavy wet rooms made from concrete and masonry. For example damage due to ingress of water and moisture in a lightweight construction is normally associated with very expensive repair work. However, they might perform fully satisfactorily on condition that they are correctly made. For other reasons, the use of lightweight bathrooms is an advantage as they are cheaper and sometimes it is necessary, when the foundation of an old building cannot support the load of a heavy bathroom. The paper presents results from investigations in Denmark of a new type of lightweight wet room floor made with 2 watertight layers separated by an inorganic layer e.g. fibre reinforced concrete. Both layers are drained to the floor gully in order to reduce the risk of damage from leaks in the watertight layer; i.e. if one layer fails, the layer beneath will be able to provide watertightness instead, i.e. the service life is increased. The results presented are based on investigations in laboratory as well as of bathrooms established in an old building.