In slate tile installation, how is the first course positioned?

In slate tile installation, positioning the first course with the face down and the backside up is important because it helps to create a stable starting point for the subsequent layers. This orientation ensures that the slate will not be directly exposed to the elements, which can affect its longevity and performance. By laying the first course this way, it also allows for proper water drainage, reducing the risk of leaks and water accumulation.

This method of installation is essential for maintaining the integrity and durability of the roofing system, particularly in areas with heavy rain or snow. Proper positioning contributes to the overall effectiveness of the slate tiles in shedding water and prevents premature wear on the tiles. While aligning with the roof edge, facing up, or layering may seem reasonable, they do not address the critical aspect of providing the right elevation and drainage strategy that comes with the correct positioning of the first course.