Attaching Unistrut and Unirac components to roof

Q. I read your article about installing solar panels at and I would like to ask you some questions.

How did you attach the Unistrut to the roof? How did you attach the Unirac to the Unistrut? What was your roofing material?

Thank you.
Sacramento CAA.

A. To answer your questions:1. A 6″- 8″ piece of unistrut with 2 holes drilled in it for 3″ or 3.5″ stainless steel lag bolts screwed to the rafters. The lags are sealed with a black roofing caulk/compound (forgot the exact name) that was put in the pilot holes that were drilled through brand new shingles/roof. These “feet” also could be installed directly onto the plywood before the shingles.

2. L feet. See page 3 here: – one side attached with channel nuts to the horizontal ~20′ unistrut, the other side was attached to the unirac. This side had slots so you could slide the unirac up and down to level out the uniracs. This was great because the garage roof was not level and it was real easy to level the whole array so that it wouldn’t be wavy.

3. Asphalt shingles on tar paper on 5/8″ plywood on 2″x3″ redwood rafters.

The solar panels are quite high off the roof, but that is great for air circulation so the panels don’t overheat.

Also, Alan, the guy who helped us out, dropped by last month and commented that they no longer install panels this way.

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