Hi All,

We are finalizing our plans for a 14kW PV installation on our shingle roof (San Francisco Bay Area, roof pitch ~ 4/12). There is a concern about the panel height off the roof surface. We would like to keep at least 6" space under the panels for adequate ventilation, and preferably 7-8".

The most leak proof way of installing L foot seems to be to use IronRidge FlashFoot or similar integrated flashing options. However, these options provide only minimal clearance off the roof surface. Even if we use XR1000 rails (the largest ones, hence provides the most clearance), the clearance off the roof surface is max 5.5". If we use XR100 rails, it is less than 5".

Other option is to use stand-offs of length ~4". That will provide a clearance of about 9". The problem with that one is it is not as leak proof as the FlashFoot. If the standard vent flashings used with stand-offs fail (rubber failure), it will leak. QuickMount PV has a product called "QBase Composition Mount" that looks promising.

My questions are:

1) Does ~5" clearance provide enough ventilation for panels? (It gets really hot here in the summer, 90+ F, although not as hot as Arizona)

2) Does "QBase Composition Mount" or similar products provide good leak proof designs?

3) If you have experience with PV installations, what would be your recommendation?