April 30, 2018 Solar Energy Written by Nathan Falde
Replacing roof with solar panels
There is a symbiotic relationship between

solar panels and the rooftops that support them. Each must complement the other to ensure good performance by both, and as long as they are both well-maintained trouble can be avoided.

But solar panels have a long lifespan, and that can create complications. Since a properly sized and installed solar array is expected to last at least 25 years, unless your roof is relatively new or recently restored (say, within the last five years), the chances are good that your roof will need to be replaced long before your solar panels stop functioning.

This could be considered a complication, but it is not an insurmountable one. Even if removal and reinstallation are necessary solar panels are a financial winner, and knowing you might need a new roof someday is not a good reason to avoid solar.
 

Have a damaged or old roof? Roof replacement prior to going solar is a good idea

Roofs can last for a long time without needing anything more than minor repairs, possibly from 20-30 years (or up to 50 years for some materials) if they were installed by a good contractor [1].

You might think installing solar panels would decrease that lifespan, but in fact just the opposite is true.

Solar panels are solid, lightweight, waterproof and weather-resistant, and their presence can add a degree of protection to a roof that might otherwise be fully exposed to sun, rain, wind, snow and falling debris during storms.

Nevertheless, roofs are still vulnerable to the ravages of time and nature, and if you see signs of damage you may have no choice but to replace your roof even if solar panels have already been installed [2].
 
The signs of significant roof damage to watch for include:

    • Roofing material that is crumbling, cracking or curling

    • Shingles that are covered with moss or mold

    • Signs of sagging, identifiable from inside the home

    • Crumbling shingles that are clogging the gutters

    • Signs of wear, tear or other damage around rooftop objects (chimneys, vents, skylights, etc.)

    • Peeling paint near the roofline, indicating excess moisture penetration

    • Water stains on interior walls

    • Leaks in the attic following rain or snow melting

    • Small holes in the roof that let light into the attic

    • Escalating levels of energy usage

Many of the indicators of a damaged roof relate to water leakage, and leakage is always a telltale sign that a roof is losing its structural integrity.

Of course, one of the best ways to avoid this trouble is to act before you actually install solar panels. If your roof is less than 10 years old and shows no indication of damage, a new roof is probably unnecessary.

But it is a good idea to ask your solar contractor to examine your roof with extreme caution and care before commencing with the installation of your new panels, since there could be early signs of damage that will be difficult for you to spot on your own. If any indications of trouble are found, roofing technicians can carry out a more detailed inspection to determine whether you need repairs or a whole new roof.
 

Cost to remove solar panels to replace roof

Regardless of the procedures used, replacing a roof is a material- and labor-intensive chore, and that makes it an expensive proposition.

As of 2018, the average cost for a home roof replacement in the United States is $7,307 [3]. How much it costs will depend primarily on the roofing material used, the heaviness or thickness of the roof, the size of your home and your geographical location.

Broken down by material choice, estimated cost ranges for a roof replacement in 2018 are as follows [4]:

  • Asphalt: $1,700—$8,400
  • Wood shake: $6,800—$20,000
  • Concrete tiles: $7,600—$21,000
  • Ceramic tiles: $11,900
  • Steel: $5,100—$22,000
  • Aluminum: $11,900—$24,200
  • Slate: $17,000—$84,000
  • Synthetic slate: $11,900—$18,900

 
Because these estimates vary so widely, there is no reliable way to tell ahead of time how much it will cost you to replace your roof. You will need to consult a roofing repair company to receive a precise figure, and needless to say there could be some sticker shock depending on the materials you prefer and the specific characteristics of your home.

One bit of good news is that most of these options can work with solar panels, which are lightweight and easily attachable to most types of roofs.

Slate is the one major roofing material that is not recommended for use with solar, since slate is relatively brittle and can easily crack and cause leaks if solar panels are mounted [5].

Another great piece of news—maybe the best piece of news, actually—is that taking down solar panels and re-installing them later is not an overly expensive procedure. While there obviously is some variation, based on the size of the project and the complexity of your initial solar installation, having your solar panels taken down and re-installed will likely cost you somewhere between $500 and $1,500, and if any contractor you consult gives you a higher estimate you should probably look for someone else [6].

This is a good bit less than the original installation, since the job of taking solar panels down and re-mounting them again is relatively quick and uncomplicated. When panels are first installed there are numerous calculations that must be made, electrical wiring work that must be completed, permits that must be obtained and so on, none of which will affect the reinstallation process.

Because they are so durable and strong and don’t consume excessive space, storage of your solar panels following the initial removal shouldn’t present any problems. But if you simply don’t have room, your solar contractor can put them in storage for you until they are ready to be reinstalled.
 

Solar panels pay off, and so do new roofs

While it would be ideal to install a new roof before solar panels go up, doing it in the reverse order is perfectly acceptable. Regardless of the modest extra expense for a solar reinstall, please keep in mind that a well-maintained and fully functioning solar photovoltaic array will likely pay for itself 15-25 years before it needs replacing, and your cumulative energy savings over time should be more than enough to cover the costs of a roof replacement (assuming you don’t choose gold or platinum as a roofing material).

Ultimately, your roof will have a limited lifespan in any case, and you’ll almost assuredly want to replace it before you try to sell your home.

A house with a new roof (less than 10 years old) and a working rooftop solar panel array will bring you a premium price if and when you do decide to sell. A 2015 study carried out by the Lawrence Berkeley National Laboratory found that an average-sized home with a solar array on top is likely to go for about $15,000 more than a similarly sized non-solar residence—and you can add a few more thousand more to that price if your roof is new and in great shape [7].

It’s clear to see that solar panels and new roofs represent a profitable and efficient investment, the value of their symbiotic relationship is undeniable.

 


References

[1] https://goo.gl/tDYT2d
[2] https://www.goodhousekeeping.com/home/renovation/a34020/when-to-replace-your-roof/
[3] https://www.homeadvisor.com/cost/roofing/install-a-roof/
[4] https://www.homeadvisor.com/cost/roofing/install-a-roof/
[5] https://goo.gl/gzgnBk
[6] https://news.energysage.com/solar-panel-roof-replacement/
[7] http://newscenter.lbl.gov/2015/11/12/premium-for-solar-homes/