Key Considerations for Installing PV Mounting Structures on Asphalt Shingles Roofs

As solar energy continues to grow in popularity, more homeowners are considering installing photovoltaic (PV) panels on their asphalt shingle roofs. While this type of roof is common in residential areas, careful planning is required to ensure the PV mounting structure is installed safely and effectively.  

In this blog, we will discuss the key factors to consider when installing a solar panel system on an asphalt shingles roof, including mounting options, weight distribution, waterproofing, and maintenance.  

1. Choosing the Right Mounting System  

There are different types of PV mounting structures for asphalt shingle roofs. The most commonly used options include:  

- Lag Bolt with Flashing Mounts – This method involves securing the solar mounting brackets directly into the roof rafters, with flashing added to prevent leaks.  

- Adhesive-Based Mounts – Some systems use industrial-strength adhesives to attach solar mounts without penetrating the roof. This is less common but useful for certain roof conditions.  

- Ballasted Mounts – These systems use weighted bases to hold the panels in place, though they are more common for flat roofs than for sloped asphalt shingle roofs.  

Choosing the right mounting system depends on factors like roof condition, local weather, and manufacturer recommendations.

2. Weight Distribution and Structural Integrity  

A standard solar panel system adds extra weight to the roof. Before installation, an evaluation of the roof's structural strength is necessary to ensure it can handle the additional load. Older roofs or those in poor condition may require reinforcement or repairs before solar panels can be installed.  

3. Waterproofing and Leak Prevention  

One of the biggest concerns with solar panel installation on asphalt shingles is the risk of leaks. To prevent water damage:  

- Installers must use high-quality flashing under the shingles at each mounting point.  

- All drilled holes should be properly sealed with weatherproofing materials.  

- Regular roof inspections should be conducted after installation to detect any potential issues early.  

4. Optimal Panel Placement for Maximum Efficiency  

The placement of solar panels impacts their energy production. To maximize efficiency:  

- Panels should be installed at the right tilt angle based on geographic location.  

- The roof should have minimal shading from trees, buildings, or other obstructions.  

- South-facing installations generally produce the most electricity in the Northern Hemisphere.  

Proper planning ensures the system generates the highest possible energy output.  

Installing solar panels on an asphalt shingles roof requires careful planning to ensure proper mounting, waterproofing, and long-term durability. By choosing the right mounting system, securing the panels correctly, and conducting regular maintenance, homeowners can enjoy the benefits of clean energy while protecting their roof investment.