Questions to ask salesman about mounting racks.

[inetdog]

some of those are railless systems that front edge. Not a fan of railless and not a fan of putting decorative front edges on as dirt/leaves/snow can get behind it.

You also generally do not want to do anything to block the natural flow of cooling air up the roof under the panels.

[Deja-vue]

I used Solarclam-p railless Mounts.
Saved me a lot of money compared to the Rail systems.
Solarclam-p.com
Cheers,

[randomuser]

I was wondering about those edges too. That's just decoration? I thought it made the system look worse. I like the sleek look with the tiles removed under panels where the panels are flush with the roof. Is that flush install worse for roof wear? The look is nice in my opinion.

[inetdog]

I was wondering about those edges too. That's just decoration? I thought it made the system look worse. I like the sleek look with the tiles removed under panels where the panels are flush with the roof. Is that flush install worse for roof wear? The look is nice in my opinion.

A flush system will not affect the wear on the roof much either way, but it will result in much higher panel temperatures. That will reduce your output on all but very cold days and may lead to faster degradation of the panels if you live in a hot climate.
The conventional wisdom for cooling is at least 4" off the roof, with no significant improvement once you go past about 6"

[peakbagger]

With respect to the height off the roof, be careful on sizing. My location is in high wind area. When I used the Iron Ridge Software a few years back I was limited on the roof gap. I believe 3" was okay but move up to 4" and they couldn't supply me a racking system to meet my wind requirements. There is calculation called wind uplift and that works against higher spacing. I think some companies are requiring edge sealing as way of getting around this.

[inetdog]

With respect to the height off the roof, be careful on sizing. My location is in high wind area. When I used the Iron Ridge Software a few years back I was limited on the roof gap. I believe 3" was okay but move up to 4" and they couldn't supply me a racking system to meet my wind requirements. There is calculation called wind uplift and that works against higher spacing. I think some companies are requiring edge sealing as way of getting around this.

Since the biggest reason for increasing the roof gap for panels installed parallel to the roof surface is to increase the cooling air flow to the bottom of the panels, adding edge sealing to allow greater spacing is self defeating.
If you need clearance for wiring, plumbing, odd bumps in the roof, etc. , that is a different story.

[peakbagger]

I agree entirely with respect to edge sealing. I suspect that salesmen looking out for the bottom line are taking a cost savings with technical limitations and turning it into a selling point to unknowing consumers.

[Mike90250]

Where there is a bird, there is a way. Photo of bird nests in between spike strips. flash tape woven into the nest too! 20160408_102618.jpg