Misinformation is rampant in the solar industry. We’ve already posted several times in response to untruths, myths, and misinformation in the solar industry. How about another one? In this episode of Solar Mythbusters, we respond to a Facebook post that generically bashes solar as damaging and dangerous to roofs.

The myth…
Ok Sports fans, we recently saw a comment on Facebook that basically asserted that roof mounted solar is done by clueless people in ways that damage the roof and create weight loads which are dangerous. This put the Solar Mythbuster into motion. Here’s the post (names withheld to protect the innocent):

Solar Mythbuster Response…
That sure is a bleak conception of solar installation. Let’s analyze each statement, one by one:

“There are no regulations as far as adding more structure to ur existing roof” Not sure what that means. I can say that there are always regulations regarding building out a roof, or adding an extension, etc. The regulations are solid – they are part of the building code for your municipality, and are enforced by the building inspector of your municipality.

“Ur adding more weight to ur roof” Yes. Indeed. However, as part of ANY REPUTABLE solar installer’s site survey, photographs and measurements are taken of:

  • The size of the rafters – are they 2”x4”, 2”x6”, 2”x8” or otherwise?
  • The spacing of the rafters – are they 12” OC, 16” OC, 24” OC or otherwise?
  • The peak to eave run of the rafter
  • Bracing/knee-wall/truss construction

From there, all materials are submitted to a Structural Professional Engineer (SE) who uses standard force and load calculations to determine the viability and safety of a solar system on that roof. Generally speaking, about 90+% of roofs we encounter can safely support solar. Now and then the SE will find scenarios where some remediative construction is required – a knee-wall must be built, or perhaps sister rafters should be installed. Very rarely do they tell us a roof is totally unsuitable for installation, and if they do, we RUN. Why on Earth would we want to create an unsafe condition for the people we are trying to help and create liability for ourselves?

By the way, the SE reports look sort of like this:

“Splitting the rafters of ur roof with 1/2 lag bolts that are required to install them” As part of the SE report (see #2 above), we are told what size lag to use. To this point, I cannot recall a single installation out of hundreds that uses lags larger than 5/16″ (about half the diameter you assert). As far as splitting rafters – that rarely happens. That said, sometimes the lag will not hit center on a rafter, and it may come out the side. But that scenario is hardly “splitting rafters”. Furthermore, I would say maybe one of every 20 lags has this problem over the course of an installation. But I stress, the rafters are not “Splitting”.

“And to be a certified installer of them, all you need is to do is take an 8 hour class
Let me state that I don’t know what jurisdiction you are in, or what certification you speak of. I will speak to our region: to participate in NY’s solar program, an installer must suffice FAR GREATER requirements than an 8 hour course. See here.

I know the rigor of this requirement. I am a NABCEP PV Installation professional and have been in the industry for more than 10 years. As for EcoMen Solar – our crews have participated in hundreds of jobs ranging from simple flat roof structures through complex penetrative flat roof installations.

Yes, there are always some fly-by-night operations out there. And those guys only highlight the relevance of the NABCEP certification. Entry level NABCEP candidates requires 40 hours of training or documented experience working in an installation organization to earn the chance to sit for the test. It’s even more difficult to sit for the NABCEP PV Installer examination. To sit for that exam, a candidate must demonstrate proof of completion of 40 hours of installer training (plus OSHA training) and that they had lead installer status on at least 3 projects taken through turn-up (you even have to provide scans of the permits).

I recommend that anyone interest in going solar make sure they only interview installation companies having one or more PV Installation Professionals on staff. Look for this logo (the number is the ID of the certificant).

Mythbuster conclusion…
The poster needed some clarification.

As a final comment…
Every industry has its share of strong professionals and weak professionals. Solar is no exception. However, unfounded and sweeping negative assertions like the one that was made are damaging the public perception of solar and therefore the industry as a whole. In this day and age its easy for verifiably FALSE arguments and assertions to spread quickly and influence many.


Too many fact-less arguments are made these days.

Too many believe them without scrutiny.


Be better. Think better.

EcoMen Solar.

Solar Solutions for New Jersey, New York, and Eastern Pennsylvania