April 12, 2018 Solar Energy Written by Nathan Falde
Solar panel roof leak
In theory, installing high-efficiency solar panels

on your rooftop should be a real money-saver. But suppose a photovoltaic solar installation caused collateral damage that offset your savings? Suppose, for example, that installing solar panels caused your roof to start leaking? This could lead to expensive repair bills, not to mention significant water damage inside your home.

It is not hard to find horror stories about roofs leaking after solar panels were installed. Check out the comments sections in articles that discuss the subject, and you’ll inevitably read heated accounts of sieve-like leakage from disgruntled homeowners.

Fortunately, this anecdotal evidence is misleading. In fact, modern solar technology has advanced to the point that roofs with solar panels should never leak, as long as qualified solar technicians are hired to handle the installation. Too often this latter standard isn’t meant, and that’s when people run into trouble.


 

How are solar panels attached to the roof?

The standard method for rooftop PV panel installation makes use of mounting brackets that attach directly to the house, through the roof and into the support structure below [1]. Multiple holes do have to be drilled to facilitate the mounting process, but the holes are filled with high-quality silicone and covered with metal flushing that prevents any and all moisture penetration.

The whole procedure is fairly simple and straightforward, and as long as it is carried out carefully and professionally, the final results should be leak-proof.

Because modern solar panels only weigh about four pounds per square foot, standard roofs are more than strong enough to support even large-scale installations without stress or strain. Nevertheless, solar professionals examine rooftops closely before installation begin, to ensure they are capable of handling the extra load.

While solar panels are built to be mounted on sloped roofs, they can still be installed on flat roofs and may not require any drilling at all in these instances. Flat-roof solar arrays are normally anchored in place with heavy ballast, usually in the form of concrete blocks, which does add some extra weight to the system but not nearly enough to compromise a roof’s structural integrity [2].
 

How to prevent leaks when installing solar panels?

Solar arrays can usually be mounted without complication. But leakage can occur if:

  • Incompetent installers are employed
  • The roof is made of the wrong materials [3]
  • The roof is already damaged at the time of installation

 
Avoiding the first problem is simply a matter of doing your homework. Before contracting any company, check to make sure they have good reviews, a lack of complaints from the Better Business Bureau, and all the proper certification and licensing expected from a legitimate solar contractor [4]. When you choose an upstanding contractor mistakes are unlikely, since experienced companies that stand by their work know how to install solar equipment properly.

Unfortunately, there are fly-by-night operators in the solar installation biz that will take shortcuts or fail to observe best practices if they believe it will increase their profit margin. For example, some contractors will install solar panels on roofs made of slate or wood tiles, both of which are brittle and inflexible and can easily crack or break if drilled through.

Many of the horror stories about leaky roofs caused by PV panels involve homeowners with roofs made from these materials, who didn’t realize they were a poor choice for solar and chose companies without the integrity to inform them of that fact.

Damaged roofs can be identified on inspection, either by roofing professionals or by solar technicians, who know the signs to look for when evaluating rooftops for PV panels. Before going solar, you should definitely pay for any needed roof repairs first, and if you know you will have to replace the roof within five years you should go ahead and replace it right away, before your panels are installed.

This might seem like an extra expense you’d like to avoid, even if it meant putting off solar.

But remember: a properly-sized and professionally installed solar panel array can pay for itself through energy savings in just 6-8 years time, and the energy savings you’ll enjoy from that time on will quickly offset the costs of installing a new roof [5].
 

Solar panels can help protect your roof

A professionally installed photovoltaic solar array will change the look and performance of your roof. Panels are super-resistant to damage or dislodgement, and even hurricane-strength winds are unlikely to uproot them if they’ve been properly mounted.

As an addition to your roof, they can offer protection against the long-term corrosive effects of too much sun, wind, rain, snow, or atmospheric pollution. Meanwhile, the panels themselves are the ultimate in low-maintenance technology. Since they have no moving parts an occasional cleaning is likely all they will require, and with an estimated lifespan of 25-40 years a solar array can deliver its protective effects long past the point you’re likely to sell your house [6].

And speaking of selling your house: a fully-functioning, fully paid for rooftop solar energy system will increase the value of your home by $15,000 to $20,000 on average, and you’ll have no problem finding buyers when you include solar as an added benefit [7].
 

Rooftop solar is a winning technology

Outside of the initial expense (which should be reduced by rebates and tax incentives), there is very little if any downside to installing a rooftop solar PV system. Through energy savings and enhanced property values it can pay for itself multiple times over, and leave you smiling and happy as you contemplate your reduced home utility costs and your contribution to the healing and protection of our environment.

If you have the roof to handle it, rooftop solar energy is a viable, affordable option, and any fears you have about it causing leaks can be put to rest, if you make sure to hire a qualified solar contractor that can recommend repairs and handle all aspects of the installation.

 


References

[1] https://goo.gl/RLvXCB
[2] https://www.solarpowerworldonline.com/2016/04/whats-solar-ballast/
[3] https://news.energysage.com/is-my-roof-even-suitable-for-solar/
[4] https://www.solarenergy.org/state-licensing-requirements/
[5] https://www.nrel.gov/docs/fy17osti/68425.pdf
[6] https://goo.gl/iKMBRg
[7] https://news.energysage.com/home-solar-power-increase-property-values-across-us/