Most residential solar panels are installed on rooftops. Rooftop installations are done faster and at a lower cost compared to a ground-based system. The roof top area to be used must face in any southerly direction and all roofing types can be accommodated.
The amount of electricity a rooftop system can produce depends on the size of the house and the shape of the roof. A typical home has a roof with southern faces able to accommodate ten to thirty solar panels.
For the best performance, the areas of the roof must not receive any shade from trees or otherwise. Some roofs are not suitable for solar panels because of their shape, orientation, or shading from trees or other nearby objects including roof pipes, dormers, and chimneys.
At our latitude, the ideal roof pitch is between 25 to 40 degrees (5:12 to 10:12), depending on the orientation. Higher pitch is better for direct south-facing, or lower pitch for east or west facing. Any roof that gets full sun exposure can be a good candidate, but lower pitch roofs (3:12 or less), are unfavorable for wintertime and more susceptible to hail damage.
Solar panels are attached to the roof using hardware that is designed for the type of roofing, wind load, and snow load. The distributed weight of the solar panels is low, so the roof does not need to be reinforced.
When correctly installed, the roof attachments will not leak or cause any damage to the roof. The system is designed to last as long as the roof.
Each type of roof has different characteristics and types of mounting hardware. Our favored brand is SnapNrack.
Asphalt flashing roof attachments use metal flashing that slides underneath the shingles to provide a secure, waterproof seal. This ensures that there will not be any leaks even if the shingles fail.
Asphalt sealant attachments are designed to attach directly to the shingles and waterproofing membrane, using the roofing material itself to provide a permanent seal.
Metal attachments are tailored to the specific brand and type of metal roof, such as pole barns with exposed fasteners or standing-seam roofs with hidden fasteners.
Tile roof attachments replace individual tiles at each attachment point with metal flashing that is shaped like the tile. Lag screws are used to attach the mounting hardware to the rafter.
Flat roofs typically use ballasted solar mounts without penetrations, where the solar panels sit in trays held down by concrete blocks; these systems require regular maintenance and are not favorable for winter climates.
