How are Solar Panels Attached to my Roof?

OMG WHY IS WATER COMING THROUGH OUR CIELING!!!

The fear about roof penetration from solar installations is definitely in the top 3 concerns of people that are serious about installing solar power, so let’s just clear the air. I don’t personally know how every company installs solar energy panels on a roof, but I know how our company does it, and that is what I’m going to explain in this article. I also know that some people shouldn’t be doing it at all.

Installation practices vary by roof. Spanish tiles are the most expensive type roofs to install PV modules on. The reason is that we have no choice but to walk on them, and inevitably break some of the tiles. The owner must have extra tiles lying around, or we must be able to find a match ahead of time to be able to replace. If not, we cannot do the job. There is also some added time spent both drilling through them and treading carefully upon them. Wood shake shingles are particularly awful as well. The easiest and thus cheapest type of roof to install solar energy on is a composition roof.

There is a unique benefit to the flat, tar-and-gravel roofs and the flat polyurethane foam ones, because you can aim the photovoltaic modules in any orientation or tilt you desire, although to build that scaffolding to put them on costs a few bucks extra. With a pitched roof you are often limited to the orientation and tilt provided by the roof, which, if perfect already, is going to be cheaper than doing a flat roof.

Spanish Tile	Tar and Gravel	Wood Shake	Composition

We use something called “fastjack” to attach to the roof. Fastjack is made by pro solar. Then we seal the crap out of it with this stuff from GeoCellUSA.

Here are some notes:

1. Yes, we stick giant lag bolts into your beams like the one with fastjack in the picture above.
2. Panels aren’t that heavy. Most of the coding requirements come from “upforce.” Basically there is way more danger to the panels catching air like a sail and ripping off your roof than there is to them weighing too much and pushing through your roof. If they are bolted to the rafters then they are attached to the infrastructure of your house and not the roof, and there are no worries.
3. We’ve never had a customer have a leaky roof because of a solar installation we have performed, and we’ve been around 30 years. The sealant we use is very high grade and warrantied for 50 years.
4. A huge amount of labor is spent finding the exact center of the rafters. There are new mounting products coming out that will reduce this labor.
5. We can coordinate with a roofer so that we come in and put the posts in, they do the roof, then we come back and do the install.
6. It’s about $1000 bucks (of course that could be less or more based on size) to pop off existing panels to let a roofer do his thing, and then put them back on, so never let doing your roof stop you from getting solar. It’s almost always better to start saving money on energy today.

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