Considering Tesla after talking to independent

[holeydonut]

Thanks willow_hiller. Not sure why the CA sales tax was assessed then.



Thanks for your reply. I do have flat lightweight concrete tile. I was concerned about this first, but a bunch of people seemed to indicate that they did install on concrete tile. Also, I talked to them on the experience line and they said concrete tile was supported as long as it was of supported weight. Perhaps this is some sort of regional policy? There are tons of houses with flat concrete tile here so I imagine Tesla not supporting this installation would be quite apparent?

Ok, good to know. Whatever you do... make sure your install gives you a quality mount on your tile roof.

I spoke with two roofers in my region and they said they've seen so many pissed off homeowners with solar on tile roofs that they now advise anyone with a tile roof to say "no to solar". I'm not a big fan of a blanket statement "no", so I dug in deeper to learn why there were problems. Here's what I learned:


1) There are four methods of mounts that work with tile roofs; tile hooks, stand-offs, tile replacement mounts, and the "three course" method.

2) Tile hooks seem great, but can be problematic since cheap/poorly fitting hooks could impact the tile below. If your installer uses hooks you have to make sure that if wind pushes down on your array it doesn't cause the tiles on the lower course of roofing to bear any unexpected loads. This could involve grinding tile or paying extra for the thickest/strongest hooks.
Example... imagine what happens if weight were on the hook pressing down on the tile below it...
SnapNrack Introduces the Flat Tile Roof Hook to Reduce Solar Installation Times - SnapNrack

3) Stand-offs are the "old school" method and involve grinding a big hole through a tile flashing under the tile. Just say NO to this method. There is no good version of this method.
Example... just imagine your roof full of those ground away tiles:
Imgur

4) Tile replacement mounts could be a good solution, but installers often find the replacement tile doesn't actually fit well with your roof tiles. But it should be a good option if you're a good candidate try to get this. I was not though.
Example... flat, S and W tiles:
The Replacements: These solar mounts for tile rooftops cut labor costs, avoid OSHA issues | Solar Builder

5) The three course method still has a bit of grinding, but involves a bunch of extra flashing and seals. If this is properly done, this mount WILL NOT LEAK. It's the "bulletproof overkill method." The solar mount will not be to blame for future leaks; those will be the fault of your aging roof or a skylight issue or something. This is costly, but worth it if your installer is game.
Example instructions I ran by my installer and made sure they said "yes" to this:
Imgur

6) Schedule to have a roofer inspect your solar right after it goes up. If they find anything amiss you're in a good spot to get it addressed before it ages and the finger pointing begins.

7) Do NOT assume some solar install/leak warranty is going to save you from leaks down the road. Pay the extra to get things mounted very well.


Tesla wouldn't even go with the hook method on my roof, so I never found out whether they'd even bother with the tile replacement or three course method.

 

[SoCalSteve]

Ok, good to know. Whatever you do... make sure your install gives you a quality mount on your tile roof.

I spoke with two roofers in my region and they said they've seen so many pissed off homeowners with solar on tile roofs that they now advise anyone with a tile roof to say "no to solar". I'm not a big fan of a blanket statement "no", so I dug in deeper to learn why there were problems. Here's what I learned:

....

Tesla wouldn't even go with the hook method on my roof, so I never found out whether they'd even bother with the tile replacement or three course method.

Holeydonut, thanks for the thorough message! Man, the info I get, the more analysis fatigue I have! For some reason your statement about Tesla (last line in the quote above) didn't show up in post above! Anyways, so was there any consensus about Telsa's ZEP mounting method, especially with regard to flat tile? I can't seem to find any info. Looks like after SolarCity bought it out, they took it off the market for everyone else. There are a couple of articles and YouTubes about it but not enough to make any judgement on it.

 

[holeydonut]

Holeydonut, thanks for the thorough message! Man, the info I get, the more analysis fatigue I have! For some reason your statement about Tesla (last line in the quote above) didn't show up in post above! Anyways, so was there any consensus about Telsa's ZEP mounting method, especially with regard to flat tile? I can't seem to find any info. Looks like after SolarCity bought it out, they took it off the market for everyone else. There are a couple of articles and YouTubes about it but not enough to make any judgement on it.

Yeah I edited my post to add that I didn't actually go through Tesla for my install. TBH I never learned much about PV or Powerwall from Tesla since they started to nickel and time me then said my roof was not a good candidate and too high (two story + vaulted).

But, based on my research Tesla will do the tile hooks recommended on this Zep guide:
https://dpw.lacounty.gov/bsd/lib/fp/Small Residential Rooftop Solar Energy Systems/LA County Recognized UL 2703 Racking Systems/Zep ZS Span System Installation Guide.pdf
(see page 39 of the PDF but says page 35 at the bottom)

Somehow they would pull this off without grinding notches and without the hook touching any surrounding tile. Seems a bit idealistic haha. I think this is why my roofer contact just said "hell no" to solar. This may also be why Tesla said I couldn't get solar from them.

Anyway I ended up going with Sunrun since they didn't think my roof was too high, and they would do the three course method (took some effort on my part to get that mount though).

 

[jjrandorin]

when I google Zep for installation, I got this video

 

[holeydonut]

when I google Zep for installation, I got this video

That video is for composition shingle roofs. SoCalSteve has flat concrete tiles. Here's a similar video for tile roofs...

But it glosses over at warp speed what I believe to be the most important part describing necessary clearances on various tile types. Plus the hook is like 2 pieces with a weld which is much different than what you'll find with Quickmount PV, Iron Ridge, or SnapNRack
Imgur

 

[jjrandorin]

That video is for composition shingle roofs. SoCalSteve has flat concrete tiles. Here's a similar video for tile roofs...

But it glosses over at warp speed what I believe to be the most important part describing necessary clearances on various tile types. Plus the hook is like 2 pieces with a weld which is much different than what you'll find with Quickmount PV, Iron Ridge, or SnapNRack
Imgur

I have concrete tiles as well, although I dont have the curved looking ones that are in that video that look more like spanish tile. They didnt have any issues with my roof, and I havent had any leaks since the system was installed in 2015. I have 34 panels on my roof (house is ~3200 square feet ish).

Of course that doesnt mean much (me not having leaks is not a predictor of anyone else not having them).

 

[holeydonut]

I have concrete tiles as well, although I dont have the curved looking ones that are in that video that look more like spanish tile. They didnt have any issues with my roof, and I havent had any leaks since the system was installed in 2015. I have 34 panels on my roof (house is ~3200 square feet ish).

Of course that doesnt mean much (me not having leaks is not a predictor of anyone else not having them).

The devil is always in the details... tile hooks could be the solution for anybody with a tile roof, but they must know the extra considerations. Tesla could not answer the extra considerations. But don't take my word for it; here's an article from SOLARPRO in 2013 (bolds added by me). They refer to the "three course method" as "double-flashing."
https://www.quickmountpv.com/pdfs/SP6.6_Oct13_TileRoofs.pdf

I've cut out the important part about tile hooks on tile roofs here...

TILE HOOKS

The use of tile hooks for array attachment has grown over the last few years. One major advantage is the lack of visible flashing, which makes for a more attractive array. Another benefit is faster, easier and less expensive installation using fewer parts, compared to the more conventional standoffs and double-flashing method.

When determining whether a roof is suitable for tile hooks, you need to know how high the tile is spaced off the underlayment. Tile hooks are often designed for a specific tile height and installation configuration, like common S tile or flat tile installed on standard 1x2-inch battens. They may not work with battenless tile installations or with elevated battens, as the tiles’ height off the underlayment might be too short or tall for the hook.

Some tile hooks offer vertical height adjustment using a two-part bolted hook with a vertical adjustment mechanism, but be aware that these adjustable-height hooks might not be as strong as single-piece hooks. Also, tile hooks tend to have lower pullout values compared with standoffs, so you must verify that the specific hooks have the required pullout and compression strength to secure the array properly for 25-plus years.

We recommend reviewing third-party engineering test data to validate that a tile hook’s load capacities meet your local permitting requirements for pullout and shear loading. When installed properly, the tile hook passes between two tiles and does not penetrate the tile surface. When using tile hooks, you have to remove part of the weatherguard lug from the bottom of the top tile. You can do this with a tuck-pointing diamond blade on an electric grinder.

One of the benefits of using tile hooks is the elimination of tile-level flashing. However, many installers fail to install the base flashing mandated by the IBC, the IRC, tile roofing manufacturers and the TRI. The TRI guidelines require installation of flashing at the underlayment or base level on all tile roof penetrations. Flashing at the base level protects the hooks’ fasteners from rainwater running down the underlayment.

 

[charlesj]

I have flat tile on my roof. I did the installation myself using tile hooks. I had time, not rushed so not an issue for me.
I nailed all my tiles down as earthquake resistance so I had to lift up a couple of upper tiles so I could get the tile off,
mount the hook that overlaps the lower tile and replace the upper tile.
Spanish curved tile is much more difficult.

 

[Vines]

Ah, fun with Tile. We had done this ourselves for many years, now we only work with a roofer to do this. We try to work with the original roofer if possible to maintain the waterproofing. The homes we work on simply cannot leak.

Another option is to remove the curved tile entirely, and replace with Comp under the PV array. Then the curved tile can be laid right back over the comp and cut right to the edge of the PV panels. The PV array ends up looking so the frame is flush with the uppermost tiles. It ends up looking really slick. This is actually imported original 400 year old Italian roof tile.

A customer we are working with now is doing the same with Slate surrounding, and Copper Standing Seam metal under the PV panels.

Holey your post is quite informative. Anyone putting hooks down on the paper without a metal under flashing or at least bibbed in with paper and even better 3 coursed is asking for a leak imo.

 

[holeydonut]

Wow that's a nice 52 panel array they fit over their garage! Don't the panels need some airflow under them to keep them a bit cooler? It does look super-slick (almost like a Tesla tile roof!). But I wonder if it negatively impacts production.

 

[Vines]

Wow that's a nice 52 panel array they fit over their garage! Don't the panels need some airflow under them to keep them a bit cooler? It does look super-slick (almost like a Tesla tile roof!). But I wonder if it negatively impacts production.

Heat is bad, but I am 100% confident that is the last thing on their mind that they may lose 2% production due to cell temp. That roof cost more than my house.

 

[holeydonut]

Considering the average house in the Bay Area is $1.6mm... that is scary haha.

I suppose if the homeowner is that wealthy they'll just pay someone to spray the panels with water ever 30 minutes.

 

[Vines]

Plenty of people drive huge SUV with 1 person inside. Wasting a few % of PV production on vanity is the same.

Lucky for me my house is significantly less than any millions, but I bought in years ago.

 

[TheTalkingMule]

I got a decent quote from an independent installer on energysage. However after Tesla’s price drop, I mentioned that I need to to evaluate their option as well and he of course mentioned some negatives:

That's the problem with trying to buy solar in the US, it's always a 1-to-1 sales process. This breeds deception in good people who started out with the best of intentions. Also why solar is 40% more in the US that literally ANYWHERE else on the planet.

Looks like your points were covered, this guys "concerns" are mostly nonsense. The only thing to worry about with Tesla is level of service and communication. If you stay on top of them, and share any concerns along the way here, you should be fine. I've been advising people to "buy" the array size that looks a hair big for their roof and let Tesla trim it down in the customization phase.

Great to see the Tesla vs local installers battle is moving forward. We're all going to benefit from this fight Elon started and the market will be better off for it. Elon set the bar with $2/Watt pricing for standard installs. Everyone else now has to adapt. Hopefully these local guys will respond with some form of up-front pricing or any big increase in product transparency. Exciting times.