Solar power has become more and more popular over the years, with solar panels popping up in neighborhoods across the country. One company that has sold solar panels for years is Tesla, the corporation that is the brainchild of billionaire Elon Musk. More recently, Musk has unveiled, not only solar panels, but Tesla’s entire solar roof.
Tesla is ambiguous about how much their solar roofs weigh, but customers have noted that they may be heavier than a standard roof made of metal or asphalt but still lighter than slate or concrete roofs. They are lighter than solar panels when panels are combined with a roof’s weight.
Solar energy is one of the cleanest and most renewable energy sources, and solar panels have been powering homes for years. However, the aesthetics of panels have deterred many homeowners from going solar, even though they could save thousands of dollars on their electric bill. That all changed when Tesla introduced its new solar roof.
What is All the Hype for the Tesla Solar Roof?
There seems to be a lot of hype surrounding Tesla’s all-solar roof since its announcement in 2016. Tesla had already offered solar panels through this arm of its ever-expanding company, and then started offering entire solar roofs that essentially replace your existing roof. If you could use a new roof, it could be a good alternative.
Tesla’s solar roofs are made of a mixture of active, building-integrated photovoltaic shingles that generate the solar power from the sun, and traditional, non-solar shingles intermixed across the roof. A main benefit of the roof is aesthetics, as it is sleek and stunning compared to bulky solar panels placed on top of an already-existing roof.
The company has advertised that it has installed more than 3.6 gigawatts of clear solar energy on around 400,000 roofs, which is impressive to say the least. If Tesla has indeed installed that many solar roofs, the weight is more than likely not an issue for homeowners. However, the weight of the solar tiles still remains unclear.
Tesla is vague when it comes to releasing the weights of their tiles, but they do say that their solar roof tiles are more than three times stronger and half the weight of regular roof tiles. However, what that exactly means as to how much an actual tesla solar roof weighs remains uncertain. However, some customers have publicized the weights.
Some Specs of the Average Tesla Solar Shingle
Even though they probably cost more, there are many reasons, beyond energy savings, why an individual would choose to get solar shingles installed on their roof over just the traditional asphalt, metal, slate, or concrete shingles. They are made of thin, building-integrated photovoltaic sheets that look nearly identical to traditional roof tiles.
This is what makes solar roofs so popular – they are much more aesthetically-pleasing that traditional solar panels. They measure much smaller, similar to the size of a traditional roof shingle, are less than one inch thick, and may weigh around 13 pounds per square foot. A standard roof installation would probably require 300-400 shingles.
The main benefit of having a solar roof is that you are saving energy on your electric bill and also helping the environment by using clean, renewable energy to power your home. The pros of entire solar roofs over solar panels are appearance and an easier installation. For one, a solar roof looks much better than bulky solar panels.
The shingles are easier to install in that traditional roofers can complete the roof similar to a regular roof without the help of solar professionals. The drawbacks? A solar roof may need more tiles to be as efficient as solar panels, which brings the price up more. Even without the extra tiles, a solar roof is definitely more expensive than solar panels:
- A Tesla solar roof can run anywhere from $60,000 and up
- Tesla’s solar panels are priced depending on the size of the system:
- $8,200 for a 4 kW system size = $2.04 per watt
- $16,400 for a 8 kW system size = $2.01 per watt
- $24,600 for a 12 kW system size = $2.01 per watt
- $32,800 for a much larger 16 kW system size = $2.01 per watt
Tesla’s Numbers Are Not 100 Percent Accurate
Note that those numbers do not include the Powerwall 2 battery and other materials needed for the installation, which would increase the prices. Although solar roofs may cost more than panels, they are much more pleasing to the eye and the entire roof weighs less than adding bulky solar panels to an already existing traditional roof.
The Tesla solar shingles do look like regular shingles, which is a definitely pro compared to the solar panels. The glass tiles are made of quartz, which makes them quite durable, and the solar system is fully integrated into the shingles themselves so the weight is kept down without added materials.
The Tesla solar roof, however, has not come without its problems. Just recently, a customer who purchased a Tesla solar roof was left without a roof and only tarps covering his home for two full months. There were numerous reasons for the delay, including the use of untested materials. How does this detract from Tesla’s credibility?
Tesla has not answered quite a bit of questions about the solar roofs, including exactly why there was such a long delay for the customer noted above. Although Tesla is very ambiguous when it comes to the total weight of their solar roofs, or even the weights of their solar tiles, there are calculations that can try to figure out how much they weigh.
Heavier Shingles Can Also Add to the Cost of the Roof
Just the Tesla roof alone could cost, at a minimum, $60,000, but could run even more. A Consumer Reports Analysis determined that a Tesla Roof may cost approximately $73,500 to install, and other reports noted even higher numbers. Does this mean you will save money with a traditional roof? Not necessarily depending on the weight.
Larger, heavier roofs equate to more material, more labor, and more time being spent installing the roof. This means more money out of your pocket to install a heavier roof. Although the roofing industry has established that the heavier the roofing shingle means the more efficient it is, roofing manufacturers are making the opposite – lighter shingles.
Following this school of thought, lighter roofs may not only provide more protection, but also be less expensive because of the materials used and labor needed for the install. Tesla roofs are more expensive because of the solar capabilities, but does the lighter roof equate to less labor?
How Much Does a Tesla Roof Weigh?
Tesla’s solar roof tiles are made with tempered glass, which may weigh less than concrete, Spanish, and slate tiles, but asphalt and metal should be about the same. A customer weighed a tile at 7 pounds, which means that can be compared to other types of tiles and shingles used on roofs based on pounds per square foot and listed below:
- Aluminum – Around 0.50 pounds per square foot
- Painted steel – Around 0.80 pounds per square foot
- Copper – Around 0.85 pounds per square foot
- Stone-coated steel – Around 1.25 pounds per square foot
- Metal tiles – Between 1 to 3 pounds per square foot
- Asphalt shingles – Between 2 to 4 pounds per square foot
- Wood shingles and wood shakes – Between 3.5 to 4.5 pounds per square foot
- Textured asphalt shingle – Between 3.5 to 5 pounds per square foot
- Spanish tiles – Between 6 to 19 pounds per square foot
- Tesla solar tiles – About 7 pounds per square foot
- Slate tiles – Between 7 to 10 pounds per square foot
- Concrete tiles – Between 9.5 to 12 pounds per square foot
The above approximate weight of the Tesla solar tile is just one example from a customer and is only the solar tile itself. When you factor in all of the other solar components required to make the roof work, the tile weight could increase to between 15 and 20 pounds, which is not half the weight of many of the examples above.
There are also additional elements that go into the weight of a Tesla roof. For example, Tesla uses a waterproof underlayment that is laid under the solar and non-solar tiles and on top of the roof deck. The weight of this piece of equipment is unknown but should be calculated, in addition to the materials to hold the tiles in place.
The main specs known are the Tesla roof tiles are 15 by 45 inches in length and come with a 25-year tile and weatherization warranty. Yet, there is no mention of the weight of the tiles themselves let alone the entire roof. Some research on calculations could compare a Tesla solar roof to a standard roof made with one of the materials above.
One Calculation of a 10 foot by 10 foot Tesla Solar Roof
According to Nature Calls, a roof made of shingles is measured by square, as noted above in the list of calculated shingles and tiles. One square contains three bundles of shingles, and this example compared the weight of Tesla PV solar tiles and Tesla glass tiles to three traditional options: tab shingles, architectural shingles, and a slate roof.
The PV tiles calculated at 7.3 pounds per square foot and the glass tiles came in at 4.15 pounds per square foot. These numbers nearly mirrored the numbers above and do make the Tesla solar tiles competitive when it comes to the weight of Spanish, slate, and concrete tiles. However, the roof itself would still be heavier than a standard roof.
Taking the calculations further:
- A shingle roof is measured by square, which is 10 foot x 10 foot, and that one square consists of 3 bundles of shingles
- 3 tab shingles = 50-80 pounds a bundle
- Architectural shingles = 65-80 pounds a bundle
- Slate roof = 300 pounds a bundle
- TESLA: PV Tile (Solar Tile) 23 pounds a bundle
- TESLA: Glass tiles – 13 pounds a bundle
Then the weights of the Tesla panels were converted into a square, which means the total numbers need to divide the weight per square by 100 in that there are 100 square feet in a “roofing square”:
- The 10 by 10 roof has 2.66 panels across and 12 panels down
- There are 32 tesla tile panels per 10×10 square
- The PV Tiles = 734.16 pounds per roofing square (10×10)
- Glass Tiles = 414.96 lbs per roofing square (10×10)
- PV – 7.3 pounds per square foot (divided by 100)
- Glass – 4.15 pounds per square foot (divided by 100)
Looking at the numbers above, it is hard to substantiate Tesla’s claim that their solar tiles are approximately half the weight of a standard roof tile. What exactly is a standard roof tile? Concrete or slate? Since many roofs also use metal or asphalt, the numbers above illustrate that the entire Tesla solar roof would weigh more than those shingles.
How Does the Weight of a Tesla Solar Roof Compare to Solar Panels?
Although solar panels themselves may not weigh more than an entire Tesla solar roof, putting them on top of your already existing roof will calculate a total weight that is higher than the solar roof itself. The average residential PV solar panels are approximately 5.4 by 3.25 feet with each module containing around 60 solar cells.
Looking at the average size of a residential PV module, they usually weigh anywhere from 30 to fifty pounds each depending on the manufacturer of the solar panels. Most roofs can handle this extra weight without issue, but it really depends on how many solar panels your roof needs to adequately power your entire home and appliances.
To compare solar panels to a solar roof, you should determine the entire weight load of the photovoltaic system. This would include, not only the panels, but mounting racks and other hardware components that make up the entire solar paneling photovoltaic system. The components probably range three to four pounds per square foot.
Although Tesla does not offer the weights of their solar panels, they do detail the four standard solar sizes and how much square feet they would cover on your roof:
- 4 kW system size = 12 panels and 240 square feet
- 8 kW system size = 24 panels and 480 square feet
- 12 kW system size = 36 panels and 720 square feet
- 16 kW system size = 48 panels and 960 square feet
Tesla has also noted that the following types of roofs can handle both their solar roof and solar shingles without issue:
- asphalt, composition shingle
- concrete tile
- metal standing seam
- rolled asphalt or torch down
- foam
Residential roofs are designed to handle at least twenty pounds per square foot, but the following roofs are said to be able to handle a Tesla solar roof, but not the Tesla solar panels:
- Corrugated metal
- Slate
- Wood shake
- Clay tile
- Metal shingle
Can You Walk on a Tesla Solar Roof?
It was mentioned that solar roofs are easier to install than solar panels. That may be true, but installers and roofers need to be extremely careful when installing a Tesla solar roof because the solar tiles are so slippery. That connects to a very important question – can you walk on a Tesla solar roof? Yes you can, but you probably should not.
If you have seen roofing contractors installing a traditional roof, whether metal, asphalt, concrete, or slate, you probably saw the workers walking across the roof without issue. That is not the same for a Tesla solar roof. Sure, you have the ability to walk on the roof, as it is definitely strong enough to hold weight. In fact, the glass is quite durable.
Tesla has touted their claims that the solar roof tiles are three times stronger than traditional roof tiles, which could be hard to believe since they are made of glass. Would you feel safe walking on a glass window? Probably not. Yet, the Tesla glass solar tiles are actually tempered glass and will not crack under the weight of an individual.
YES: A Tesla Solar Roof is Durable Enough to Walk On
The glass used by Tesla is stronger than tile roofing in that it has been put through a chain of chemical treatments, which have made this tempered glass incredibly durable to withstand the weight of someone walking on it. And, it is not just Tesla that is making these claims; they are backed up by three of the respected groups that test shingles:
- American National Standards Institute (ANSI) – tested for hail
- American Society for Testing Materials (ASTM) – tested for wind
- Underwriter Laboratories (UL) – tested for fire
Tesla’s latest solar roof, the Solar Roof V3, earned an ANSI Class 3 hail rating, which means the shingle can withstand a 1 3/4–inch steel ball that is dropped from twenty feet. The shingles can withstand 166 mile-per-hour winds and have the highest Class A UL 790 fire rating. These three high ratings further illustrate the durability of the product.
So, if Tesla’s glass shingles are durable, strong, and can hold up to huge pieces of hail, hurricane winds, and class-A fires, why would they not be safe to walk on? When it is a professional roofing contractor, this durability makes them extremely safe. However, for an everyday individual who does not have a roofing background, the answer is no.
NO: A Tesla Solar Roof is Too Slippery for the Average Person to Walk On
The Tesla shingles are extremely durable, so you will not damage them by walking on them. However, they are still made of glass and that is very slippery, especially when they are wet. Even professional roofing contractors are recommended to wear a harness when working on a Tesla solar roof to protect them from falling off of it.
On one hand, the slippery nature is a benefit in that snow and dirt will slide right off of the roof. Since your solar tiles will not be able to generate the energy from the sun if they are covered with snow or dirt, having slippery tiles is a major benefit to helping them work to power your home.
However, this slippery nature should encourage you to avoid walking on your Tesla solar roof. This is especially true after it has rained or if your shoes are wet, as this could lead to disastrous results. If you do have the need to walk on your Tesla solar roof, you should wear non-slip shoes and possibly a harness to keep you safe.
There may be reasons that you will need to clean your Tesla solar roof. In fact, a Tesla customer recently even inquired about recommendations for sticky shoes so that he or she could walk on the solar roof. The roof seemed to be extremely slippery even when it was totally dry. Using the right shoes, you may be able to safely walk on your solar roof.
What to Look for When Calculating the Tesla Solar Roof Load
As noted, your Tesla solar roof can withstand quite a bit of pressure, from hurricane winds to golf-ball size hail, to the damages of fire. But are there load limits for a Tesla Solar Roof? In order for your Tesla solar roof to stay together, intact, and in place, it has to be able to resist permanent and temporary loads that push down and up onto it.
Although Tesla does not discuss the load limits of its solar roof, there are some customary loads that are expected and can be inquired about if you are speaking with a Tesla service professional or roofing contractor before anticipating the purchase of a Tesla solar roof:
- Dead load – The weight of the roofing structure, which includes the solar and non-solar tiles, as well as any materials used to permanently attach the solar roof. For example, an average dead load of an asphalt-shingle roof is 15 pounds per square foot while a clay-tiled roof may be as much as 27 pounds per square foot. The Tesla solar roof will probably run somewhere in between.
- Live and environmental loads – The weight of any temporary object placed on the roof. This includes anyone working on the roof and is normally around 20 pounds per square foot or environmental issues such as snow.
- Uplift load – An average uplift load limit presumes that it can handles winds of approximately 90 miles per hour, which is not a problem for the Tesla solar roof due to its impressive wind-resistant rating, and anticipates a load of around 20 pounds per square foot.
When discussing the calculation of loads with a roofing contractor, you will need to determine the different loads listed above and whether or not your Tesla solar roof can bear those loads. Other determinations will include both the vertical and horizontal load path. Determining your roof’s structure and maximum weight can assist this process.
If the combined load above is more than the maximum weight, your support structure could collapse. Now, because Tesla’s solar tiles come right around the middle when it comes to weight, and they do not need the same heavy materials that the solar panels require, having a collapse due to a Tesla solar roof is more than likely rare.
Why Does Weight Matter?
As you start researching roofing materials and comparing them to Tesla’s solar roof shingles, you will begin to discover the differences in the weights (as noted above). Since these materials vary so much in weight, your roof may weigh as little as 1,750 pounds or more than 5,000 or even 10,000 pounds. Tesla probably comes in lower.
Roofs are heavy due to the shingles and the materials that hold everything together. Since Tesla’s shingles weigh in somewhere in the middle, they should be fine for any standard home. They come in much less than concrete or slate and will probably be just a bit heavier than the average asphalt or aluminum.
Some of the materials that hold the roof together do need to be heavy to protect the entire roof from weather-related events like hurricane winds and storms. However, the overall weight of the roof should be light enough so that it does not weigh down the home while still protecting it. Homes may move or shift more under heavier roofs.
A lower-weight roof can certainly protect a home from weather-related incidents and has a less chance of collapsing after a fire. In fact, after the disastrous earthquake in Kobe, Japan in 1995, many residents rebuilt their homes using low-weight roofing materials in lieu of their traditional heavy roofing materials so that they were better protected.
Conclusion
Although Tesla is very ambiguous about how much their solar roofs weigh, you can approximate the calculation of your Tesla solar roof after having an understanding of the amount the tiles weigh according to pounds per square foot. Tesla is exceptionally confident in the durability of its solar roof and customers have noted this as well.
One would question whether they should worry about the weight of the roof since the tiles seem similar to other standard tiles and shingles, or whether the solar tiles will start to degrade over time and lose their efficiency. Since a Tesla solar roof costs so much more than a traditional roof, this may be the more important question to contemplate.