Drip by drip, water from leaky plumbing accumulates in the wall – so gradually that it often goes unnoticed for weeks on end. The homeowner doesn’t become aware of the problem until damp patches start to appear on the wall or ceiling. This is not an isolated occurrence: insurance companies in Germany process over a million claims for water damage due to leaky pipes every year. The most common cause is the failure of aging plumbing systems, but other sources of water damage include burst pipes due to the freeze-thaw cycle, or badly installed plumbing, or flooding. This can subsequently lead to other problems such as the appearance of mold, the blistering of building materials and wall coverings, or more serious structural damage. And as if this wasn’t enough, damp treatment companies increasingly have to deal with further complications because of the wide diversity of building materials, which are used in all possible combinations – from blockwork with integrated insulation to damp-proof membranes. Specialist knowledge is required to choose the right treatment method.
In response to requests by industrial customers, researchers at Fraunhofer IBP investigated a number of different construction materials with respect to their drying behavior. They analyzed four floor structures consisting of concrete screed and EPS (expanded polystyrene) insulation in combination with three wall structures consisting of insulation-filled clay blocks. Different wall and floor drying systems and techniques were used to dry out the materials. The scientists built four identical test setups in the controlled-environment chamber at Fraunhofer IBP in Stuttgart, and introduced water at floor level over a period of two weeks to simulate the effects of flooding. Throughout the experiment, the same temperature and relative humidity was maintained in all four setups – in other words, identical environmental conditions. In three of these test setups, different sub-floor drying systems were used to remove moisture from the wall: the first was equipped with an absorption dryer, the second had wall-mounted infrared panels, and the third consisted of a high-speed fan blower operating at maximum speed. The fourth setup served as a reference. The systems were left in place for three weeks, then switched off for three days, and then switched on again for a further two weeks.
The experiment delivered measurement data from which the scientists were able to derive exhaustive information on the drying process, the effectiveness of the different drying methods, and the drying result.