For all its aesthetic qualities, natural slate has limitations in that it cannot be formed into complex shapes. This means that weather tight construction in natural slate can only be achieved by significantly overlapping the slates, threefold at any point. The result is high labor costs, weight issues and performance limitations.

By contrast, an interlocking slate can achieve a weather tight layer through the use of interlocking weather bars. This limits the amount of overlap required between each slate thus reducing the amount of material needed, with big savings in installation time and cost. Computer-aided tile design backed up by wind tunnel testing means that performance can also be enhanced allowing an interlocking slate to perform at far lower pitches.

Products that provide cost benefits on the one hand often demand compromise on the other. The Fangxing slates are an exception to the rule. These slates make use of natural materials with a riven finish to give a truly authentic natural slate appearance.