Interest in commercial solar is growing across Edmonton. Business owners want lower energy costs, tenants increasingly value sustainability, and financing options have made projects easier to fund. The City of Edmonton’s Clean Energy Improvement Program, for example, lets eligible commercial property owners finance energy efficiency and renewable energy upgrades and repay them through their property tax bill. Program details and intake change, so always check the current terms directly with the program.
But there’s one question many building owners forget to ask before signing a solar contract: is the roof ready for 25 years of solar panels?
On a commercial flat roof, the answer to that question can save, or cost, a lot of money.
Why Roof Condition Comes Before Solar
Solar panels are designed to last 25 years or more. Your roof might not be.
Imagine installing a solar array on a roof with eight years of life left. When the roof needs replacing, the entire array has to be removed, stored and reinstalled. You pay for the roof replacement plus the cost of taking the system down and putting it back up. You also lose solar production while the work is done.
That’s why the most important rule for commercial solar is simple: the roof should last at least as long as the solar system. For many older buildings, the smartest plan is to replace or restore the roof first, then install solar on a brand-new roof.
5 Roof Questions to Answer Before Installing Solar
1. How much life does the roof have left?
Get a professional roof assessment that estimates remaining service life. A roof with 20+ years left may be ready now. A roof that’s 15 years old or more usually deserves a serious conversation about replacement first.
2. Is there moisture inside the roof?
Wet insulation is invisible from the surface but can be found with infrared scanning or moisture surveys. Installing solar over a wet roof traps the problem under equipment that’s expensive to move.
3. Can the structure carry the extra load?
Edmonton roofs already carry significant snow loads, and solar panels can change how snow drifts and where it builds up. A structural review is often needed to confirm the building can safely handle the panels, racking, ballast and snow together.
4. How will the panels be attached?
Commercial flat roof solar systems are usually either:
- Ballasted: held down by weight, with few or no roof penetrations, but heavier
- Mechanically attached: fewer weights, but more penetrations that must be flashed properly
Every penetration is a potential leak point. Each one needs to be sealed and flashed to the roof manufacturer’s standards, ideally by or in coordination with your roofer.
5. Will the roof warranty survive the solar installation?
Some roof manufacturers have specific requirements for rooftop equipment. Work done without following them can affect your roof warranty. Before installation, confirm with your roofing contractor and the manufacturer what’s required.
Why SBS and Single-Ply Roofs Both Need Protection
Whether your building has an SBS torch-on roof, TPO or EPDM, solar installation brings new risks to the membrane:
- Foot traffic during installation and future maintenance
- Dropped tools and equipment
- Ballast blocks or racking rubbing on the membrane
- New penetrations for conduit and attachments
Ask for protective pads under ballast and racking, and walkway pads along service routes. A good solar plan also leaves clear access to drains, roof edges and rooftop units, so the roof can still be inspected and maintained.
Plan the Roof and Solar Projects Together
The best results come when the roofer and solar installer coordinate from the start. A combined plan can include:
- Roof assessment with a moisture survey and remaining-life estimate
- Structural review for snow and equipment loads
- Roof replacement or repairs first, if needed
- Insulation upgrades during re-roofing, which add energy savings on top of the solar savings
- Solar layout designed around drains, rooftop units and service paths
- Penetration and flashing details agreed on by both contractors
- Documentation for both the roof warranty and the solar warranty
Doing the roof and the solar in the right order avoids paying twice for the same roof area.
Don’t Forget Snow
Solar arrays on flat roofs change how snow behaves. Panels can create drifts, shade parts of the roof so snow lasts longer, and make snow removal harder. Talk with your designer about:
- Array layout and spacing for snow drift
- Keeping drains clear and accessible
- How snow will be managed safely around the panels in winter
The Bottom Line
Solar can be a smart investment for Edmonton commercial buildings, but only on a roof that’s ready for it. Start with a professional commercial roof inspection to understand the roof’s condition and remaining life. If replacement makes sense, plan it before the panels go up. Learn what’s involved in new flat roof installation in Edmonton, and how upgrading commercial roof insulation during re-roofing can add even more energy savings.
