Is My Roof Strong Enough for Solar Panels?

You may want to put solar panels on your roof – but can it hold the weight?

 The vast majority of roofs can easily support the weight of solar panels with no additional support required. However, the weight of your solar panel system varies between manufacturers.

Keep reading to find out everything you need to know about whether or not your roof is strong enough to support the weight of solar panels.

95% of Roofs Can Easily Handle the Weight of Solar Panels

The vast majority of roofs in the United States have no trouble supporting the extra weight of solar panels. Roughly 95% of roofs can support solar panels with no changes required.

However, it’s never a bad idea to check if your roof can support the weight of solar panels. After all, roughly 1 in 20 roofs can’t support the weight of solar panels.

A solar panel can weigh up to 5 lbs per square foot. Unless your roof is old or in bad condition, it should have no trouble withstanding this amount of weight. 

Minimum roofing codes in the United States require residential roofs to carry anywhere from 20lbs to 100lbs per square foot, which means your roof should have no trouble holding solar panels and mounting equipment. 

Talk to a licensed solar panel installation company in your area. Or, contact a third-party architect or structural engineer before you install panels. These professionals can evaluate your building, then determine if any changes need to be made to support the added weight of solar panels.

How Heavy Are Solar Panels?

Solar panels and their mounting equipment typically weigh around 2 to 4lbs per square foot. 

As solar panel technology has advanced, solar panels are becoming lighter and more efficient. Today’s top solar panels, for example, tend to have 60 cells or 72 cells while weighing less than 2.5lbs per square foot. 

The average-sized home needs around 400 to 600 square feet of solar panels, with each solar panel taking up roughly 18 square feet. 

Overall, a home’s average solar panel system, including panels and mounting equipment, should add around 1,000 to 2,000lbs of weight to your roof. That may sound like a lot. However, when distributed over your roof, it’s just 2 to 4lbs per square foot, which is more than enough weight for your roof to handle.

Residential Roofs Are Required to Carry a Minimum of 20 to 100 Pounds Per Square Foot

The average solar panel weighs around 2 to 4lbs per square foot. Meanwhile, the average residential roofing code requires a minimum load tolerance of 20lbs per square foot. 

Even if you stacked multiple panels on top of each other and encountered a heavy snowstorm, you’re unlikely to break your roof.  

In fact, some areas require residential roofs to carry a minimum of 100lbs per square foot. Wintry climates, for example, have stricter roofing codes because of snow.

Overall, your roof should hold a minimum of 20lbs per square foot of weight without issue – even if you have an older roof. 

What Happens to Solar Panels and Roofs After Heavy Snow?

If you live in a snowy climate, then you may be concerned about what happens to your solar panels and roof with the added weight of heavy snow.

Generally, snow only impacts your solar panels and roof in extremely rare cases of heavy snowfall. 

Each solar panel has a pressure rating, which determines the amount of weight the panels can withstand before they’re damaged. Most panels have a pressure rating above 5,000 Pascals (Pa), which means they can easily withstand roughly two to four feet of snow accumulation without damage.

Your roof, meanwhile, should withstand even more snow without risk of collapse. Snow tends to weigh between 5lbs to 20lbs per cubic foot, depending on its density.  

Is Your Roof Suitable for Solar Panels? Other Things to Consider

Other things to consider before installing solar panels on your roof include the following:

Age of Roof: Solar panels can weigh up to 5 pounds per square foot. If your roof is more than 20 years old, then you may want to check if it can support the weight before installing panels.

Condition of Roof: Is your roof in good condition? If your roof has any damage, like leaks or missing shingles, then you need to repair this damage before installing solar panels. Some damage can affect the structural integrity of your roof. Other damage can increase the chance of a leak, which may be difficult to fix after installing solar panels.

Orientation of Roof: If you’re installing solar panels in the United States, you want your solar panels to face south – or towards the sun’s direction for most of the year. Depending on the orientation of your roof, it may or may not be suitable for solar panels – even if it’s undamaged and can withstand the weight.

Type & Slope of Roof: You can install solar panels on a flat roof, although it requires additional mounting equipment. Consider the type of roof you have and the slope of your roof before installing panels.

Area Surrounding Your Roof: Does your roof have clear surroundings? Does it get lots of light? Or is your roof blocked by trees? Depending on the area surrounding your roof, it may or may not be suitable for solar panels. 

Work with a Professional Solar Panel Installer to Determine If Your Roof is Suitable

Is your roof suitable for solar panels? Work with a professional solar panel installer to minimize the risk of damage to your home.

A professional solar panel installer could recommend a professional inspection from a structural engineer or architect if you’re unsure about the condition of your roof. Professional installers also take steps to minimize damage to your roof, prevent leaks, and maintain the structural integrity of the entire system.

Final Word

Solar panels are not as heavy as some people think, and the vast majority of roofs can easily withstand the weight of solar panels – even if there’s several feet of snow over top of these panels.

The average residential roof in the United States must carry 20 to 100lbs of weight per square foot, according to roofing codes. In comparison, the average solar panel system, including panels and mounting equipment, weighs 2 to 4lbs per square foot. 

However, if you have an old roof or a roof in poor condition, then consider talking to a professional installation company, structural engineer, or architect to verify your roof is safe for solar panels.