Abstract: | Using a specially devised apparatus, the Trondheim Division of the Norwegian Building Research Institute has tested five types of concrete roof tiles for water tightness, using a traditional clay tile as a reference. The general conclusion is that, with the superior performance of modern concrete tiles, there is no reason why they should not be used for a roof pitch down to 15 degrees, though account must be taken of end overlaps, geometric form, tile detailing and the sub-roof construction. The results, it is suggested, expose the limitations of present test methods, which are based on experience with traditional practices. |