Installing A Commercial Rooftop Solar PV System: Part 2 in Our Solar Photovoltaic Series

Installing A Rooftop Solar PV System Toronto

There is more demand than ever for rooftop space to host solar photovoltaic (PV) panels. In fact, over one-third of new solar PV capacity installations worldwide are rooftop projects. Part one of this three-part series discussed what a PV system is, the financial benefits to commercial property owners, and factors to consider when planning a solar PV system.   

In this second installment of the series, we discuss the important role the roofer plays in the project’s overall success and the steps your roofer will take to prepare your roof for solar.  


Read Part 1: Is a Solar PV System Right for Your Commercial Building? 7 Questions to Ask


The Roofer’s Role in a Successful Solar PV Installation

With a rooftop solar power system, it stands to reason that the roof must be able to support the solar array and meet the customer’s expectations. Your roofing contractor will take these steps to make sure your roof is suitable for the PV installation:


  • Install, repair, and inspect the roof to determine if the roof, in its present condition, can support a solar array. Older roofs, or those lacking the necessary structural requirements, may need repairs or replacement before moving ahead. 
  • Assess the roof’s condition and estimated useful life to help determine if it needs replacement before solar installation.
  • Ensure that any roof penetrations made while installing the panels and mounting racks are correctly made watertight and sealed.
  • Provide recommendations on ballast blocks, and sacrificial layers of membrane that might be required beneath mounting systems, and electrical wire gangways.
  • Provide pre- and post-installation inspections to assess the baseline condition and any damages as a result of installation.


The solar company, the structural engineer and/or other experts for the property will design the appropriate type and specific design of the system based on a variety of issues, such as budget and situational factors including orientation, sunlight hours, shading studies, and roof surface area.


Commercial Roof Solar PV Installation in Toronto


The two main options are either a low-profile racking that sits +/- 1” above the roof surface or an elevated system that sits on elevated HSS steel platforms 4-6 feet above the roof surface.


Steps to Avoid Damage to the Roof

With the roof acting as a working platform, it’s crucial that the roofer and installation company collaborate to protect the roof and solar equipment throughout the process. Safeguards include laying down plywood walkways where necessary, planning proper anchor points, and avoiding punctures by using equipment with inflatable rubber tires. Hosting methods such as the use of cranes and/or telehandlers will need to be reviewed for safety and damage control.


Solar PV Installer Roof Damage



11 Steps on the Installation of Solar Panels

You might ask what activities the solar PV contractor undertakes to prepare the roof for installation of a solar power system, in coordination with the roofer, if and as required. Here are the primary steps: 

  1. Staging and Logistics: The solar PV contractor must overcome challenges such as roof obstructions, sub-optimal roof orientation, the roof’s load bearing capacity, membrane warranties, and more.  
  2. Scaffolding Staircase: While working at heights, a scaffold staircase platform is often erected to safely access the roof.
  3. Mounting, Anchoring, and Racking: The solar PV contractor measures and installs mounting structures, racking, and the anchoring system to keep the panels secure and aligned at the correct angle. The roofer installs the anchor point penetrations on an as needed basis. 
  4. Electrical Grounding: With the panels in place, the system is wired to generate electricity and send it back into the power grid.  
  5. Solar Inverter: When selling the power to the utility, the solar PV contractor installs the solar inverter to convert DC current generated by the solar array to AC current used by the utility.  
  6. Inverter Bonding: The solar PV contractor installs the junction box, solar battery, and other electrical devices when the system includes an inverter.
  7. Conduits and/or cable trays: Installing conduits or cable trays protects the wiring leading from the PV array to the inverter and from the inverter to the electrical service panel.
  8. Wiring: The solar PV contractor runs the wire and makes all the electrical connections.
  9. Safety Labels: The solar PV contactor affixes required safety and danger-related labels where needed.
  10. Monitoring: With the wiring in place, the solar PV contractor connects the system’s on-line monitoring system to provide feedback on system outages and power generation. 
  11. Start and Test the Array: System startup is completed and operations commence with power generation in place. 


Hire an Experienced Team

When planning for a commercial rooftop solar PV system, choose a knowledgeable, experienced roofer you can trust to prepare your roof, work effectively with solar PV installers, and communicate with other trades to work out equipment compatibility, supply, and installation issues.

A high-quality roofer will be able to address questions such as:

  • What types of roof penetrations are required and how are they best installed?
  • Will the PV and related module installation necessitate the replacement of some or all of the roof?
  • What steps will prevent damage to the roof or other equipment given the added foot traffic and staging of equipment on the roof surface during installation?      


Find out if Roof-Mounted Solar PV System is Right for You

A qualified roofer like Elite Roofing can advise you on options for making your roof ready for solar PV panels. Our experts know how to work with landlords, solar PV installers, and structural engineers to help optimize the best path forward to maximize your roof’s longevity, minimize maintenance, and make your solar PV system well worth the investment. Contact Elite Roofing today.