Tesla Solar and Water Leakage

They install on flat roofs?

When I had panels installed about 20 years ago, half of it was on a flat roof, we did a new roof first with mounts installed and flashed by our roofers. That system was not done by Tesla/Solar City.

About six years ago I had to remove that system because of failing BP modules. I ordered a replacement system from Solar City. They would not touch the existing mounts on the flat roof. I even offered to hold them harmless for a roof leak. But I somehow got far enough along that on the regular composition shingle roof until a internal lawyer said no to reusing the mounts there. But since they had already agreed to the install they ended up paying a roofer to remove the existing mount points so the roof was "restored" then they did a standard install with their ZEP solar feet.

I see the merits of their standardized approach. Coordination with another vendor can get costly. But it sucks for us when we want slightly custom.

I'm assuming if they install on flat roofs they also warranty the work. Do you know what kind of mount they use? If I was the customer I would prefer a zero penetration mount on flat roof. I can also imagine that if they have good roof people working that there would be no practical difference between doing the penetrations before or after. The extra cost of doing after is probably more than offset by the savings from not having to do multiple trips to coordinate.

Roofers have to rework roofs all the time so there is nothing magical about it doing up front other than easier on the roofer. Another anecdote, on our current house. We also had the mounts installed ahead of time. Somehow an error crept in and the rails slowly drifted down across the roof line. When panels were installed you clearly see it. They ended up cheating the panels slightly so the panels would look square to the roof but if you look closely you can see they are shifted slightly as you move across the roof. The error wasn't obvious until the rails and panels went up so going up front doesn't always result in easy wins.

Final anecdote, I have a SolarCity installed system on the same room as in the story above. The first system was installed in 2002, I expanded it with SolarCity in 2008. So the second system was a retrofit. Neither system's mount has leaked. I'm in the Bay Area and I think we probably get similar weather to Los Angeles area for aging purposes. This is on composite shingle roof, not a flat roof but it is a data point.

 

Since when do they install on flat roofs?

 

Tesla just installed 8 panels on my flat roof.

 

Looks like they are using Chemcurb which is a good product for this application.

Unfortunately you will not retain the new roof warranty, unless the roofer approves and warrants the Tesla work (which they usually wont)

As to the statement that they will use less penetrations, it looks to me like the flat roof shown required 18 mounts for 8 modules. Typically I would have used between 8-14 mounts for that same installation, so definitely not accurate that they are using less roof attachments, assuming it goes as shown in @SoCal Dave pictures.

 

I don't know exactly. I was looking at doing it myself and the roof mounts only had two lags going into the roof. It seemed like it would be difficult for it to leak with all the sealant and mounting hardware around it.

I had the underlayment for the tiled roof and the rolled asphalt just replaced prior to the panels being put down. My roofer has given me a 20 warranty and offered to inspect the roof after the panels were installed. He was happy with what Tesla did.

 

The flat roof is covering a 1000' sq ft addition which includes part of the master bedroom, other bedrooms and kitchen.

 

I have the warranty from both the roofer and Tesla. If there ever is a problem, I'll be calling the roofer first. As I mentioned above, they came out and inspected what Tesla did and didn't see any issues with it.

 

Nice, good deal in that case! Hope you got it in writing.