I hired NSR to install a steel roof on my house in March 2020. While they fulfilled their initial obligation: A new steel roof is on my house. I am not satisfied with the workmanship and the lack of response to honour the warranty. Bottom line: I would NOT do business with them again.
I decided on long steel panels with unexposed fasteners because of the low pitch of my roof. However, this was misleading as several dozen exposed fasteners were used along the edges of my roof and at some joints. I also expected single long steel panels from the edge of my roof to the peak. Two panels were required, one overlapping the other, joined with fasteners and sealant along the middle of the roof.
There are rubber washers underneath all these fasteners to prevent leaks. The fasteners were overtorqued so that the rubber squeezed out, exposing them to sunlight, which will reduce their lifespan (spot for leaking & corrosion).
I also have been hearing "popping" noises throughout the day. I suspect temperature changes cause the steel panels to expand and contract. Since the panels are fixed onto the roof, they are not allowed to move and rub up against each other or the fasteners. Since I have vaulted ceilings and no attic, the sound transmits into my house.
Also, caulking and gaskets used to seal the panels to the roof vents have started to separate/tear. NSR have yet to come in to do a service call.
The sad thing is that a simple Internet search show solutions for thermal expansion, unexposed fasteners, and installing long steel panels. NSR was very communicative - until they received final payment. I do not expect for them to honour any warranties.