Too often I see architectural details that are over- or under-designed. If they are over-designed, the result is likely a much higher price for the building owner. Also, over-designed roofs many times have the unintended consequence of failing prematurely. On paper, the detail looks like it will last a lifetime but experience shows some of these details just will not work in the field. Under-designed roofs just cannot stand up to the 100-year life cycle of a slate roof. The details the NSA brings forth in this publication have been time-tested and provide a standard way for designers to create a roof design that will stand the test of time.
I believe if this book can become the standard from which all slate roof installers, designers and building owners can work, then we will all win. When the details are correct the first time around, the building owner will end up with the best roof possible without a bloated budget caused by inefficient design; the designer does not end up with a strained relationship with the contractor and building owner because of poor design; and the contractor is able to correctly install a long-lasting slate roof and create another satisfied customer.
The 2010 NSA manual has become the main source of information for slate roofing for my roofing company.