Determination of freeze/thaw resistance of masonry facade
Water freezing in façades surfaces results in repeated mechanical stresses leading to cracking and flaking of material. The mechanism occurs during the late winter when sun warms the façade during the day but the core of the wall remains frozen. If the façade holds much water during these weather conditions the water will freeze and thaw cyclic. This leads to mechanical stresses and fatigue, which can result in cracks typically 2-10 mm into the surface.
It is tricky to simulate the phenomenon. A try is made in the standard CEN/TS 772-22 ”Methods of test for masonry units – Part 22: Determination of freeze/thaw resistance of clay masonry units”. An analysis of that method has been carried out in “Frost resistance of clay masonry units: In-depth experimental study of the European method” from Technische Universität Dresden. At RISE, the method has been developed somewhat further for Nordic wall constructions.
We can offer testing according to our developed method. Both brick façade and plaster façade can be tested. As there are no absolute or general requirements, comparisons are recommended, for instance of different surface treatments or apparently equal products from different suppliers. But a general guideline is that a good quality brick façade can endure 100 freeze/thaw cycles without relevant damages. A plaster façade cannot be expected to endure as much.
The test objects shall be about 40×40 cm facade surface. They can be built or cut out from an existing facade.