Welcome back to our “Installing Solar On…” series. Did you know that the National Roofing Contractor’s Association (NRCA) categorizes roof systems into two main types: low-slope and steep-slope? Low-slope roofs typically use weatherproof membrane roofing materials like TPO, EPDM, PVC, and modified bitumen, and are installed on slopes of 3:12 (14 degrees) or less. On the other hand, steep-slope roofs mainly feature water-shedding coverings and are installed on slopes greater than 3:12 (14 degrees). Check out the chart below for a visual of a low-slope, 3:12-pitch roof profile.
When planning the installation of a low-slope rooftop solar array, it’s crucial to start with a thorough structural evaluation of the roof deck and the building. Consider the age and type of roofing materials to ensure the right steps are taken to preserve the integrity of the roof. For a comprehensive approach, remember to factor in roof drainage, dirt buildup, roof traffic, and safety access.
Let’s dive into some important design considerations to keep them at the forefront of our minds.
Water Intrusion
In most low slope roofing applications, water intrusion is kept at bay by flashing the attachment points. Different low-slope roof coverings will have different flashing requirements.
Wind Resistance
Wind uplift could move or rip off and ruin the roof surface if the system is not engineered for the correct wind resistance. There are three zones for wind resistance analysis:
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- Field Zone (interior) — lowest wind loads.
- Perimeter Zone (ends) — middle wind loads.
- Corner Zones — highest wind loads.
Fire Resistance
The PV system must be engineered with materials to match the roof’s fire classification. This fire rating for PV components is governed by UL standards, and roof systems are classified for their level of fire resistance:
- Class A (highest rated; 6-ft max. spread of flames).
• Class B (8-ft max. spread of flames).
• Class C (13-ft max. spread of flames).
Make sure the flashing matches the roofing manufacturer’s installation manuals and remember that rooftop PV systems shouldn’t interfere with roof maintenance. It’s always a good idea to work closely with the roofing manufacturer and roofing contractor to ensure everything runs smoothly, although that is often impossible.
The roof should already be in good condition before installing PV and should, at minimum, last as long as the PV system being installed. Removing and redesigning a PV system after only 10 to 15 years is a considerable time, labor, and expense commitment.
EcoFasten provides professional solar installers with solar mounting options ideal for low-slope roofing. Check out the sturdy, multi-purpose 44-R, the direct-to-deck solar attachment, an installer favorite for over a decade.
Or ECO-65, also a direct-to-deck solution, uses a larger base plate with multiple fastener points for optimum load dispersal.
If you’re looking for a super-strong post & base solution for installation on new residential comp shingle low-slope roofs, QB-1 has you covered.
And finally, if you haven’t already, meet SimpleGrip-SQ (the “SQ” is for the square shape). The self-flashed base plate works on roof pitches with pitches ¼:12 and up. Because the base is compressed between two layers of SimpleGrip-SQ adhesive, a watertight seal is created without the need for additional flashing.
EBoS (Electrical Balance of System) Integration
Solar installation involves several critical factors that significantly impact system effectiveness and durability. Key considerations include module efficiency and maximizing energy production. Racking and mounting systems must be strong and durable to support PV modules and withstand environmental conditions like wind and snow, ensuring safety and longevity.
Electrical accessories are vital for optimizing energy conversion and minimizing maintenance costs. Addressing these factors during installation ensures maximum energy production, system reliability, and return on investment. The electrical balance of system (eBoS) accessories play a crucial role in maintaining the overall safety and functionality of the solar system.
For successful solar installations, you can rely on our eBoS accessories without hesitation – they’re designed to complement our mounting systems and provide maximum functionality, covering everything from wire management to conduit and bonding, right down the Junction Box.
Visit us online to learn more! And make sure to take advantage of our Elevate E-Learning Training Certification Program, designed specifically for solar PV installation professionals who want to take their careers to the next level. It equips you with the skills and knowledge required for installing top-of-the-line rooftop mounting systems and solar roof attachments. The program offers extensive on-demand training courses covering the EcoFasten portfolio products. We award certification based on the type of roof, namely Composition Shingle, Metal, Tile, or Low-Slope. You can also opt for one of our NABCEP-Accredited recertification courses!
EcoFasten, an Enstall Company, has established a reputation for being one of the industry’s leading innovators by providing expert solutions for mounting solar PV on any roof. EcoFasten’s broad portfolio of solar rooftop mounting systems and attachments stems from the direct needs of solar PV installers. EcoFasten takes pride in providing the right solution for every application.
