Wondering what the best system to use on a flat roof is? Everest has some answers and we are working on new products as we speak. Let’s take a look at existing ballasted solutions as well as fully attached systems from Everest.
First, let’s chat about roofs. The solar industry tends to call these “flat roofs”, but in the roofing world it is referred to as a low slope roof. There is typically no such thing as a “flat roof” because there is always some sort of slope to promote water drainage, but when you hop on the solar coaster you just have to get on the crazy ride and go with the flow 😊 (pun fully intended).
Most low slope roof installations are ballasted, but some installers are seeing the benefits of a fully attached system as well. It really depends on the application and site-specific variables to determine what system type works best. Everest provides solutions for both. For a ballasted system we have the D-Dome Railless² System.
The D-Dome Railless² System is a dual-tilt system, often referred to as a “east/west system.” The dual-tilt uses modules on both sides of the racking system to allow for more kilowatt density and less ballast on the roof. By having modules on both the east and west side of the roof you can avoid inter-row shading and fit more modules into tighter spaces. Again, depending on the site and roof conditions this system may or may not be advantageous. The benefit of using Everest’s free online design tool, Base 3.0, is that you can design with D-Dome, or any other Everest racking system, on a specific roof and see if it will be the best system for your project.
For fully attached systems, installers typically use a tilt system or install flush to the roof plane. For tilt we have our CrossRail Tilt Up system.
This simple system uses a short piece of rail as the back leg, repurposing the short rail cut offs that are often thrown away or recycled from job site rail-end cut offs. This is accomplished with our Tilt Connector bracket that allows for easy adjustability to roof undulations before or after modules are installed.
Online you can find a design guide to see what lengths are needed to get various tilt degree angles. Tilt legs are built, giving the installer the proper tilt angle on the roof, then the attachment rails that support the modules are attached with a Climber set. This is where CrossRail acquired its original name.
The tilt assemblies are then attached to our standard L-foot or a new product just released by Everest called the T-Foot X. This foot eliminates the need for an L-foot altogether and provides a standoff with a built-in attachment point. This is a single piece mount to make it much easier to install and connect to the rail or tilt leg. The T-Foot X can also attach to the rail directly for a flush mounted system that sits even with the roof plane.
Common low slope roof types in the US include TPO, EPDM, rolled asphalt, tar and gravel. Rolled asphalt roofs can be found on residential and commercial buildings.
Rolled asphalt roofs are very common nationwide and tend to be a fairly simple installation depending on the substrate of the roof and construction. The most common mounting solution for these types of roofs tend to be standard post and base standoffs with an L-foot attached to the top. These are also typically installed with a pitch pocket sealing product like ChemLink’s E-Curb.
The new T-Foot X product allows you to install a single piece mount with no need for an additional L-foot and attaches to the rail or tilt leg directly. The benefit is a faster install and less components. The T-Foot X also can easily be installed into a 4” ChemLink E-Curb. This is a no brainer for installers who already use standoff posts and ChemLink E-Curbs. This same method of mounting with pitch pockets or E-Curbs is also a method that can sometimes be used on tar and gravel roofs by safely removing the gravel in the location of mounting and flashing.
TPO, EPDM, and other membrane type roofs tend to be a bit more of a sophisticated roofing system that has many layers and/or insulation.
These roofing systems typically have metal roof decking and sometimes wood sheathing as well under the roofing surface material. This system can be on top of metal or wood beams, depending on the construction.
It is common for installers to core drill through the roof and insulation to access a structural member or the metal decking to attach to. This is determined by the installer, engineers, and the site conditions of the building for proper structural attachments. Many different factors such as wind, snow, pullout and shear capacities, roof weight capacity, parapet walls, roof obstructions, building height, and many more that will be outlined by the local conditions and requirements.
Ballasted systems are often used on these membrane roofs, but it is essential to understand the construction and the roof manufacturer’s requirements for installation of ballasted systems on these roofing systems. The roof material can be mechanically fastened or adhered to the roof. This is may also determine if the roof manufacturer will allow ballasted systems on the roof and/or require protection pads or slip sheets to protect the roof surface material.
With roofing systems becoming more and more standardized, there are now many options to mounting solar to the roof in a safe and code compliant method. Everest continues to work with solar installers and roofing manufacturers to understand the challenges and provide solutions that can help. With the international experience of our parent company K2 Systems, Everest has worked through various product types to bring more innovation to the US market. Our D-Dome Railless² System has proven to be a unique system while our CrossRail Tilt Up system uses a more standard method to attach to the roof. Both have shown how installers benefit from simplicity and innovation and we continue to grow with our customers.
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