I would buy this roof again in a heartbeat
I had an Interlock roof put on several years ago and I am not sure I agree with the statement "more expensive, sure". While it does cost more to put on the roof, I think the payback more than covers the extra price. I am sitting in my attic office, a place that got cold even with heat this time of year, it is warm now. It stays cooler in the summer as well which saves on cooling costs. The sales person told me that it would be the case but I really didn't believe it. I would buy this roof again in a heartbeat.
The materials that you used were of the highest quality
The materials that you used were of the highest quality. I recognize that the ventilated, insulated plywood used for the insulation of the roof, and the slate-pattern aluminum shingles were the materials that were specified in the original quotation and we are very satisfied with this material. However, what particularly impressed me was your voluntary use of the high quality RoofTopGuard II vapour barrier that your staff felt would give us a better end product, given the site conditions. This material upgrade clearly demonstrated the concern that you have for the quality of work you do.