Solar Roof Installation Tips

[holeydonut]

Wow, this homeowner in Florida got a short-changed underlayment... I guess they're supposed to use two layers?

Tesla Solar Roof buyer left without roof and tarps over his house after 2-month-long nightmare - Electrek

 

[jboy210]

Wow, this homeowner in Florida got a short-changed underlayment... I guess they're supposed to use two layers?

Tesla Solar Roof buyer left without roof and tarps over his house after 2-month-long nightmare - Electrek

Only one layer on our house. Worked fine in the March rainstorms when it was directly exposed, and since then with the solar tiles above.

 

[wjgjr]

I am a bit confused by the article, because they discuss switching from 2 layers of Firestone to one layer of something else. However, one of the images (I assume of that house) in the middle of the story clearly shows Firestone SA-FR:

https://electrek.co/wp-content/uploads/sites/3/2020/10/IMG_0524.jpg

If it is of the house, either the photo is out of sequence, or they used SA-FR on at least part of the roof. Did they switch mid-job? I was thinking they were suggesting the entire job used the different material.

We also had the SA-FR and had no issues with the single layer during install or since. Given that Firestone appears to position it as a premium product for metal roofs (CLAD-GARD Metal Roofing Underlayment) I wonder if Tesla was trying to save a few bucks using something cheaper. If so, it seems to have back-fired for them. I certainly hope it works out for the owner and that Tesla makes it right as best they can.

 

[MXDogCrate]

Well, this is a timely conversation on UNDERLAYMENT. Earlier I stated the tear off/decking sub commented they had brought in double the amount of underlayment needed?

Well, guess what showed up today? A different underlayment. Pictures attached. The driver stated this was the “new, improved underlayment”, but to a layman, it does look like generic no name product.

Cobalt Ultra I FT Synthetics

I haven’t been introduced to our project manager yet, but this certainly warrants a conversation. I’m guessing most here would opt for the name brand Firestone if we have a choice.

Word is there are two other solar roof installs within 10 minutes of us. Grateful for this conversation.

 

[wjgjr]

View attachment 595961 View attachment 595962 View attachment 595963 Well, this is a timely conversation on UNDERLAYMENT. Earlier I stated the tear off/decking sub commented they had brought in double the amount of underlayment needed?

Well, guess what showed up today? A different underlayment. Pictures attached. The driver stated this was the “new, improved underlayment”, but to a layman, it does look like generic no name product.

Cobalt Ultra I FT Synthetics

I haven’t been introduced to our project manager yet, but this certainly warrants a conversation. I’m guessing most here would opt for the name brand Firestone if we have a choice.

Word is there are two other solar roof installs within 10 minutes of us. Grateful for this conversation.

I know nothing about the product shipped to you and only know anything about the Firestone product because it was installed on our roof. Since Firestone is probably a better-known brand (at least for consumers) and is what Tesla has been using, I would definitely have a conversation with the lead about why they are using this Cobalt Ultra instead.

That said, on paper, the Cobalt Ultra may be superior. It seems to have a larger temperature range, can be installed in lower temperatures, and can be installed for longer before needing to be roofed over. And it is possible it is less slippery to work on (both make marketing claims about grip, though I know our installers said the Firestone was slippery.) If anything other than price is driving Tesla's change, I wonder if they want something they can install all year in more places than the Firestone.

 

[dhquigley]

That IS interesting (picking up on our thread from the other conversation). I will say, the Firestone was VERY slippery and they could not even go up first thing in the morning. Had to wait for it to dry. Likely costs us 1-2 days over the duration of the install. If this is superior in that respect, it would be worth something to Tesla, assuming they can work out the bugs.

 

[jboy210]

That IS interesting (picking up on our thread from the other conversation). I will say, the Firestone was VERY slippery and they could not even go up first thing in the morning. Had to wait for it to dry. Likely costs us 1-2 days over the duration of the install. If this is superior in that respect, it would be worth something to Tesla, assuming they can work out the bugs.

I can see them changing underlayment. They installed our roof in March, which can have morning frost. Numerous times I was sitting at my desk and heard the thud of a 200-pound roofer slipping. After about 2 days of this, they decided they would not start until 10 AM or so when the frost sublimated off. Even then they sent a guy around with a leaf blower to speed the process and test for slippery spots.

With that said, this new stuff had better perform at least as well as Firestone SA-FR does in rain.

 

[MXDogCrate]

I’m assuming (hoping ) it’s Cobalt Ultra. Nothing on the labeling uses the word “Ultra.”

 

[MXDogCrate]

Stupid question: did Tesla apply the underlayment or the sub who applies the OSB. The sub is telling me they are putting down the underlayment.

 

[jboy210]

Stupid question: did Tesla apply the underlayment or the sub who applies the OSB. The sub is telling me they are putting down the underlayment.

In our case the answer was both. We were part of the first 100 installs of the V3 SolarRoof. They used our install as a way to train a local roofing company and Telsa people.

 

[dhquigley]

For us it was (almost) entirely the roofing company pre-Tesla. The Tesla folks occasional had to place small pieces along edges and trim, but the roof was mainly covered in SA-FR before the Tesla people arrived.

 

[wjgjr]

For us it was (almost) entirely the roofing company pre-Tesla. The Tesla folks occasional had to place small pieces along edges and trim, but the roof was mainly covered in SA-FR before the Tesla people arrived.

This is what we had, and it generally makes sense for normal operations. The underlayment needs to go down right after the old roof is removed, so having the same crew do it is the logical approach. If the Tesla crew is delayed by a couple days finishing up an old job, it should not be a major issue for the house once the underlayment is on (still might be a headache for the owners trying to plan around the install.)

 

[MXDogCrate]

The OSB is down. Sub says waiting for inspector. Then they’ll lay the membrane before Tesla arrives.

Worried we won’t be able to talk to the PM about the membrane before our goes down.

 

[MXDogCrate]

Our roofing sub just left. He said they are definitely NOT using the Firestone SA-FR and have been told the FT Synthetics is the new material going forward. Interesting that we have both on the job site.

Also, the inspection was conducted by video! Even the sub was surprised! Okay, on to the underlayment!

 

[jboy210]

Our roofing sub just left. He said they are definitely NOT using the Firestone SA-FR and have been told the FT Synthetics is the new material going forward. Interesting that we have both on the job site.

Also, the inspection was conducted by video! Even the sub was surprised! Okay, on to the underlayment!

Our city was doing inspections via video until a couple of months ago. Better than before when they were not doing inspections for almost 3 months.

Let us know you think about the FT Synthetics product. I am curious to see if it is less slippery when wet. SA-FR is very slippery when wet. Since FT Synthetics is based in Canada you would think working in cold and wet weather would be a high priority.

 

[MXDogCrate]

Not sure what I think matters, but I will ask the PM and post here. Hanging around 20-35% humidity here. Was doing the rain dance before the project started.

It is curious that the problem install in FL shows Firestone on the roof.

 

[TSleuths]

Yes FT synthetic is based in Canada but the product FT Cobalt FR is made in China as the above picture shows. The product "FT Cobalt FR" is likely new as it gets no hits on google. Tesla's solar shingles are UL listed with an A fire class rating. The system gets the A rating from the Firestone CLAD-GARD SA-FR underlayment which is designed to underlay metal roofs. Perhaps Tesla is being forced to try to find an alternative as the product was not intended to be used as they had been. Firestone specifies "The product is not intended for Residential Applications". Most worrisome is the product was not designed as the primary covering, instead meant to underlay metal roofing. So what is this new China underlayment and what are its characteristics? Has it been tested by a national lab? I bet not or it would be published somewhere.

It's true that most of the FT synthetics products have great traction characteristics.

 

[MXDogCrate]

On the FT Synthetics website, they did revise installation instructions as of September 18, 2020.

 

[TSleuths]

I just read all the instructions for "Cobalt Ultra" and they mention nothing of Fire Resistance (FR). The product on your roof is "FT Cobalt FR". I'm just trying to point out that the solar roof product is UL listed, as is the Firestone FR. The Firestone FR gives the A fire rating. Would you be ok with a modified bitumen underlayment that is not listed with UL? What about your insurance co.? Also note that UL has an agreement with ASTM that might cover the same requirement.

 

[dhquigley]

It is interesting that the Firestone product documentation says, multiple times, that it is not for residential use. I wonder why and I wonder if part of the reason Tesla looked to switch was because Firestone could get out of warranty obligations to Tesla because of the residential use, and this way if there is a problem and customer makes a warranty claim against Tesla, Tesla has someone to go back to. I did not see a similar limitation against residential use on the FT documentation. Definitely will be curious to see when Tesla updates its documentation and this gets a little more explanation/coverage.