As you are well aware by now, I do not buy, nor sell things.
When I come upon something exceptional however, I must bring it to your attention.
Mr. Osterman is a well respected roofing professional, with vast experience in all things roofing. This book sits on my desk, and will highly recommend it to anyone who may be in the roofing discipline.
The book is very substantial, and covers virtually all aspects (including some things you cannot imagine), and is different from the $1,500.00 I spent on roofing books. The books required for the Florida State Certification (that's the CCC 1325620 number following my name), are (to me, dated, and rather cold).
Mr. Osterman brings you a great deal of knowledge gained over 62 years in the discipline, and speaks with authority. You will be well served to include this book in your library.