It has now been two years since the installation of (the) metal interlocking shingles on the roof of my residence in Ottawa. As I indicated to the salesman at the time, if after two years I was totally satisfied with the installation and performance of my new roof I would take the time to extol the virtues of the Interlock system. To date, I have indeed been most impressed with the performance of my roof. Prior to installation of the Interlock system, I was required to change the asphalt shingles on my roof every eight to ten years.
Ottawa, Ontario
