Roof Repairs Before Solar: Repair, Restore or Replace?

Thinking about installing solar panels? Great idea, both for your wallet and the environment! Energy efficient… clean… green… and combined with a battery, can keep you powered at night too. 

However, smart investment though it may be, your solar installation also needs to be planned because solar panels are a long-term investment. Good ones last some 25+ years, so popping them on a roof that needs a touch of TLC, or worse still, a major overhaul, isn’t a good idea. 

Planning Roof Work? Do It Before You Install Solar Panels

What IS a good idea is spending a bit of time now checking the condition of your roof and tacking any maintenance BEFORE installing those panels. It could save you a lot of hassles, and expense, down the track. 

So, what should you be considering in terms of pre-solar roof maintenance?

Does it look a bit washed out, faded, and in need of a lick of paint? What about those repairs or upgrade you’ve been putting off? Now is the perfect time to get them done!

Why Painting Your Roof After Solar Can Be an Expensive Mistake

It’s a common enough thing to think you can get your roof repainted with solar panels installed. The painters can just go around them, right? 

Unfortunately, the reality is that unless the paint underneath the panels is in good shape, they’ll probably have to be removed. And reinstalled… That’s expensive, and chances are great to good you’ll also run into various government regulations, even though you’re just reinstalling your system.

NSW Solar Panel Regulations: New Install vs. Reinstall

Combine Roof Repairs, Painting, and Solar for Maximum Efficiency and Value

As you can see from the table, installing solar panels before undertaking any necessary roof work is doubling up on many of the associated costs of installing solar panels. Once for the new install, and again for the reinstall… 

Why not avoid the expense and get your roof attended to BEFORE the installation. Combine any roof repairs, and painting with the solar installation for maximum efficiency. And minimal hassle.

How Roof Colour and Material Impact Solar Panel Efficiency

Did you know that the colour of your roof, and what it’s made of, can actually impact the efficiency of solar panels? True story! 

Heat Retention and Solar Output: What Studies Show

Most of us know that dark colours absorb heat. Light colours reflect them. Roofs are no different; a dark roof will absorb a lot more heat than a light one. While this is fine in very cold climates where roofs should retain heat, it’s not so good for solar panels or our warm temperatures.

Studies in fact show that the hotter the area around the panels is, the warmer the panels get, and the less efficient they are. Conversely, the cooler the panels stay, the more efficient they are.

Solar panels work best when the temperature is around 25°C. Their efficiency drops by 0.3–0.5% for every 1°C above 25°C, depending on the panel’s temperature coefficient. Roof-mounted solar panels are also usually 20–40°C hotter than the surrounding ambient air temperature. So, the cooler you can keep the roof, the cooler (and more efficient) your panels will be.

Interesting point – solar panels operating in 0°C temperatures on a sunny day can actually exceed output capacity!!

Choosing the Right Roof Type for Optimal Solar Performance

But solar panel efficiency doesn’t just depend on roof colour. Roofing material matters, too. Modern metal roofs for example have a reflective coating and, while you might think the radiating heat makes the panels hotter, the reverse is actually true. The heat is reflected away from the roof so it, and the panels, stay cooler. Steel roofs also cool down very quickly, which again increases solar panel efficiency. 

Tile roofs on the other hand not only absorb heat (up to 95% of sunlight), they also retain it for longer. So, an uninsulated dark roofing tile is probably your solar panel’s worst enemy, particularly if the panels are mounted very close to the tile surface without adequate airflow. 

Painting dark tiles with a lighter reflective coating will considerably improve their thermal properties and solar panel performance.

Why Roof Health Should Be Checked Before Solar Installation

Colour and roofing materials however are just part of the solution. Your roof also needs to be ‘healthy’ or in good repair. 

Avoid Damage, Leaks, and Future Costs

Solar panels are a long-term investment, and installing them on a deteriorating roof can compromise the roof itself. 

Many houses for instance have timber roof support structures. 

Timber can rot if the roof leaks. It’s subject to insect damage like termites if not treated properly. Even with treated timber, a nail hole can still allow insects and borers to get into any untreated areas within the timber via the hole. 

Adding the weight of solar panels, particularly a large system, could lead to structural failure. And damage the panels.

Spending money on a thorough roof inspection now, before you install the panels, will avoid expensive mistakes, spot any issues with the roof, and give you the opportunity to repair them now before they get worse.

What to Look For: Cracked Tiles, Rust, and Sagging Structures

But before you call your roof repairer in Sydney, you can check a few things yourself. Look for:

• Cracked or missing tiles
• Rusty metal sheets
• Sagging rafters

Damage to tiles and roofing sheets may have caused damage to underlying roof structures, especially if these are wooden. Sagging rafters indicate deeper issues with the roof structures. If these issues aren’t caught and repaired, they could wind up costing you a small fortune. Fix them now, before they grow into very expensive surprises. And definitely before you add solar panels on top.

Repair, restoration or full replacement: which does your roof need before solar?

Solar panels commonly remain in service for 20 to 30 years, so ideally the roof underneath them should not be likely to need major work halfway through the system’s life. As a rule of thumb: isolated problems like cracked tiles, failed pointing or a single leak are repairs, and a relatively minor repair now can prevent a much more complicated job once solar is installed. A structurally sound roof that looks tired, with worn coatings or widespread cracked pointing, may suit a restoration, which can cost substantially less than a full replacement. Widespread deterioration, advanced corrosion or structural problems may make replacement the more economical option, but that decision should follow a roof inspection.

If an inspection shows that your roof is nearing the end of its life, replacement may be more economical than restoring it immediately before a solar installation. For Sydney and NSW homeowners weighing up that option, Aussie Roof Repairs has a free roof replacement cost calculator that uses aerial roof measurements to provide an indicative replacement estimate before an on-site inspection.

Can you paint or restore a roof that already has solar panels?

For a full roof restoration or coating, the panels will generally need to be removed first. Coatings need to reach the whole surface, including under the array, and overspray on panels reduces their output. Painting around fixed panels leaves unprotected roof beneath them, which defeats the purpose. The practical sequence is: panels off, restore or paint, panels back on, which is why the smart money restores or paints the roof before solar is ever installed. Reflective roof finishes can reduce roof surface temperatures, and solar modules generally operate more efficiently at lower temperatures, although the effect on an individual system depends on roof material, panel clearance, airflow and other factors.

What does solar panel removal and reinstallation cost?

This is the number that makes roof timing matter. Removing and reinstalling a residential solar system for roof work can run into the thousands once you count safe disconnection and reconnection by a licensed electrician or an appropriately qualified solar installer (Australian Government guidance recommends an installer accredited by Solar Accreditation Australia), panel and rail removal, storage, reinstallation and recommissioning, and any replacement of aged mounting hardware that cannot be reused. Check the installer and manufacturer warranty conditions before panels are removed or reinstalled. Every dollar of that is avoidable by doing the roof first.

Common questions

Should I replace my roof before installing solar panels?

Not automatically. If an inspection shows the roof is nearing the end of its serviceable life or is likely to need major work during the expected 20 to 30 year life of the solar panels, replacement may make sense before installation. A sound roof may only need repairs or restoration.

Can you paint a roof with solar panels on it?

Not properly. For a full coating the panels generally need to be removed so the finish covers the whole roof, and overspray reduces panel output. Paint or restore before installation, or budget for panel removal.

How much does it cost to remove and reinstall solar panels for roof work?

It can run into the thousands for a residential system, covering licensed disconnection, removal, storage, reinstallation and recommissioning. The exact figure depends on system size, access and hardware condition.

Does roof restoration affect solar panel performance?

The main benefit is making sure the roof is sound before the panels are installed. Reflective roof finishes can also reduce roof surface temperature, and cooler solar modules generally operate more efficiently, although the size of any improvement varies by roof and system design.

Roof Repairs and Solar: Smart Scheduling Saves You Money

Doing your roof repairs when you install solar is smart scheduling. 

Trusted Roofing Services Can Help You Plan Ahead

At Efficient Energy Group we often work with vetted roofing professionals who understand how to check and prepare roofs for solar installation. Plan ahead, and make sure your roof is fit for (solar panel) purpose.