Are Your Solar Panels Too Low on a Flat Roof
Here in our blog and on our website, we’ve talked a lot about the problems caused by solar panel installation on low slope or flat roofs. it’s not that solar panels have to cause problems to the roof, but often because of the installation and the overall drive in the market in the economy to do things faster and cheaper, it ends up that people take shortcuts when there aren’t any guardrails to prevent those shortcuts. We see it happening here in the bigger picture as well, as regulation and oversight is removed all over the federal government. The effects will be profound, in time.
Because there’s not enough clear rules nor enforcement in place, a lot of PV solar roof panel installation companies do their work without taking the remainder of the roof system into account and often they do this work without consulting with an actual flat roof specialist as well. We recommend having a roof flat roof specialist work together with the client as they have a third party solar panel installation company install their PV system.
Some of the problems that we see with PV panel installation can be seriously consequential, from a monetary perspective. In many cases we’ve seen solar panel companies bolt directly through rooftop coping without proper applications or provisions to seal the connection of the structural bearing point from the panel system to the building frame. In many cases leaks have cost thousands of dollars of damage. We have seen other cases of improper fasteners, and insufficient provisions or protection of cabling and damage to roof copings. Overall, we recommend having a roof specialist not only be involved in the project but also look at the work of the PV companies after they’ve completed their installation to make sure there’s no significant damage to the roof membrane or roof system.
Here though, in a particular case of the roof shown in the picture below, there’s a different type of problem unrelated to damage. Here, it’s difficult to even check for damage because the solar panels have been installed so close to the roof membrane that it’s almost impossible for someone to access the roof membrane without removal of the panels themselves. We recommend the panel company install the panels with more clearance, it’s not difficult to add a purlin system that raises the panels above the roof membrane, even just a little bit more would be enough for a person to access if they had to, especially when they need to in an emergency to check.
This limited amount of space is so tight that it leaves almost no clearance, not even for someone to just stick their head inside and get a look around. It would essentially be near impossible for someone to pinpoint an area of leakage without removing, possibly, multiple PV panels. PV panel specialists might be able to remove their own panels quickly, but it’s still complicated for clients to coordinate all of the rework between the PV panel installers and other contractors as well.
Another detail pops up in these pictures as well. There’s ductwork on the upper side of this roof. Since this is the roof of a rear addition at the back of the building, unlike the typical Washington DC row home, this roof slopes, not from front to back but from the starboard side to the port side. In other words, the roof slopes from side to side, and that is not typical. That is just a detail of the configuration though and the real point applies both to roofs that slope from one side to the other side or roofs that slope like the more typical configuration or layout from front to the back. In this case, since the duct is at the upper side of the slope, a leak that emanates from the duct would likely be very difficult to troubleshoot and locate, if the leak travels downwards, following the slope that runs under the panels. Since that part of the roof is nearly totally inaccessible, it will be hard to confirm that it is not the area of the leak entry. Often with duct leaks, the leak can enter at the duct but then run downward toward the lower side of the roof before it becomes identifiable on the underside of the finished ceiling below.
The real big problem here, more than anything else though, is that the tight space between panels and the roof membrane doesn’t allow for someone to look at the root even to just visually observe the conditions. In this coming week, we will look at other photos from this roof and others roofs as well where solar panels have been installed.
We provide this information here on our blog, and our website, to help our customers and future clients, and we recommend every building owner in DC who values the longevity of their roof (and their investments) and building use a contractor who values the simple and important principles of proper roof construction like Dupont Roofing DC. Our company specializes in flat roofing here in Washington DC and we’re happy to help building owners of almost all types. Learn more about our company and the proper techniques of working with roofing on historic buildings in Washington DC here on our blog at DupontRoofingDC.com, and you can call us at (202) 840-8698 and email us at dupontroofingdc@gmail.com. We are happy to help and at least talk through options.
