Take one Canadian Art landmark, add a steep steel roof, 60 feet in the air on a sloped site, and a 15kW - 3 Phase solar electric array and what do you get? The McMichael Canadian Art Collection project.
The McMichael Canadian Art Collection houses Canada's largest collection of Canadian Art most notably the best collection of Group of Seven work in the world. Directly under the PV array is gallery space - a roof leak could ruin a priceless work. For this job, a Standing Seam Metal Roof was used. It allowed us to fasten our racking without making a single roof penetration. We attached directly to the standing seam with special clamps made by a company called S-5!. The S-5!s with a standing seam metal roof are a premium combination but if potential roof leaks will keep you up at night you might want to consider them.
The second challenge with this job was the height and steepness of the roof combined with the sloped site. An aerial lift or crane would not work on this slope. To deal with this we used custom scaffold along the entire length of the eave below where we were working. This gave us a staging area for equipment and tools as well as an added measure of safety for those down below if a part or tool was to slide away on us. This type of work environment requires extra planning to ensure few trips up and down the scaffolding as this can add tremendously to installation time and installer fatigue.
Our last big challenge on this job was dealing with the irregularly shaped roof surface. The wall construction is log with stone piers in between. Over time, the logs settled, but the stones didn't. This left a terrible hump in the roof above the stone pier. We felt that the lines of the solar array would further accentuate this hump so we used a racking system that allowed us to 'mellow' the hump. It was a long and systematic process but it worked out well in the end.