It’s no secret that rooftop solar installations are good for the environment and your pocketbook. Not only does generating solar power reduce dependence on fossil fuels and the emissions involved in transporting them, but with solar PV, you also develop an electricity-producing asset that creates positive cash flow after a simple payback period.
It also saves the environment with a significant reduction in electrical consumption during production and the same in pollution resulting from transport. Using continuous rails is a common practice for mounting your solar PV array but choosing a rail-less mounting system saves you even more money on residential, commercial, and industrial applications.
As the name “rail-less” implies, this type of mounting system eliminates the need for bulky rails and the financial expenses associated with railed systems. As a result, rail-less solar mounting offers you a range of cost savings.
First, let’s take a look at how rail-less components secure PV modules to your roof and why this method is so effective.
How Do Rail-less Mounting Systems Attach a Solar Array to Your Trapezoidal Ribs?
Direct-attach solar mounting uses your trapezoidal ribs as the rails. Metal panels are structural roof coverings. This means, in most cases, your trapezoidal panel ribs can carry the loads associated with your system into the supporting structure – both the dead loads of your solar array and the wind uplift loads your PV modules will experience.
With rail-less mounting, you gain better load distribution because you can place a direct-attach component anywhere on the ribs—and your roof is protected when you use attachments sealed with factory-applied, 60-year, closed-cell EPDM gasket material, tested for water-proofing to ASTM E2140 protocols.
Trapezoidal roofing comes in an array of panel profiles, material types, and gauge thicknesses. To determine the right attachment location and number of needed attachments, always engineer your system using products that have been proven through certified load testing conducted in a third-party A2LA accredited laboratory.
When you’re attaching into the sheeting only, be sure to use mounting components that secure into the sides of the rib crown—not the top. An angled design will place your fasteners in shear (rather than the typical direct withdrawal of top-down attachments) to give you much greater holding strength. Certain brackets attached in this method can achieve up to 5 times greater holding capacity than top-down mounting components.
The option of a versatile attachment that fits virtually any rib profile up to 3 inches in width can be extremely beneficial when installing a rail-less mounted solar array.
Depending on your project needs, attachments may alternatively be secure through the sheeting into the deck or structure below for more support to accommodate strong winds or snow loads. This is typical of most residential and some light commercial projects.
When this is the case, look for an attachment that uses factory-applied butyl sealant when attaching into the valley of your metal roof—one that has also been tested to ASTM E2140 certified protocols.
Why Is Rail-less Solar Mounting Less Expensive?
Once you’ve taken rails out of the equation, you’ll save money during every step of the process.
Forget High-Priced Materials and Freight
Compared to most solar racking systems, rail-less systems are a small fraction of the weight – around 15 percent. That 85 percent weight reduction over rail components means your materials’ costs are lower, and shipping is much less expensive.
Rather than flat-bed shipping for rails that may be fabricated in 16-foot-lengths or longer, you can receive your components in standard package delivery boxes. Depending on the size of your job, you can save more than 60 percent in shipping costs alone.
Avoid Expenses for Storage and Transportation to the Jobsite
Paying to store rails is another expense you can cross off your list when using direct-attach components. Rail-less systems are so compact that they take up 90 percent less warehouse space, so you won’t need a separate storage area.
Getting compact, direct-attach components to the job site is a snap. Instead of paying for a flat-bed truck to bring rails to the site, simply stow the boxes in the back of a short-bed pickup or even the trunk of your car (a 250kWp requires about 750 pounds of direct-attach parts compared to 4,750 pounds for railed systems).
Put More Money in Your Pocket With a Faster Install
Would you like to save an average of 35 percent or more on labor? Rail-less solutions come pre-assembled to make your job run smoother. Your job just got easier without the need to lift rails on the roof, place them, and perform in-field rail cutting to fit roof sections.
For example, as compared to rail systems requiring up to 12 different components, the S-5! direct-attach system requires only three. The installation is a straightforward process. Just align your first row of modules, then use that row as a jig for the rest of your array – completing the job in a simple lay-and-play manner. Installation is so easy and fast; some installers get jobs done in less than 90 seconds per module.
Rail-less mounting leverages the financial benefits of installing a solar PV array. Why spend more for rails when direct-attach mounting can use the inherent strength of your trapezoidal panels, be engineered to withstand your project’s specific loads, and save you money in multiple ways? Get the full value out of your investment by going rail-less.
This is a guest post from our partner, S5!
About McElroy Metal
Since 1963, McElroy Metal has served the construction industry with quality products and excellent customer service. The employee-owned components manufacturer is headquartered in Bossier City, La., and has 14 manufacturing facilities across the United States. Quality, service and performance have been the cornerstone of McElroy Metal’s business philosophy and have contributed to the success of the company through the years. As a preferred service provider, these values will continue to be at the forefront of McElroy Metal’s model along with a strong focus on the customer.
Topics: Metal Roofing, Solar, Accessories, Cost
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