Slate roofs are commonplace in England. If your home has a slate roof, you might be wondering if it’s possible to add solar panels without damaging its integrity.

The answer is yes, but it requires a specialised approach.

We walk you through everything you need to understand about the installation process.

Will Installing Solar Panels Damage My Slate Roof?

This is the most common question we get asked here at Agenda when a client has a slate roof.

When done correctly by an experienced professional, the installation will not damage your slate roof. The key is to understand that a slate roof installation is different from one on a more common concrete tiled roof.

The wrong way: Drilling directly into the brittle slate. This is a sure way to crack the tiles, compromise the roof’s waterproofing, and lead to future leaks.

The right way: A professional installer uses a less invasive method. We are slate roof specialists. Using the new proprietary slate flashing kit, we no longer need to remove any slates like we used to, which eliminates the cracking and breakages that inevitably occur when the slates have to be removed.

• We cut the slate in situ using a special template and steel shield to remove the least amount of slate possible and protect the roofing felt below.
• We fix the roof hook to the rafter so that the mounting structure is tied to the structure of the building.
• We then slide the plastic flashing under the slate to ensure the roof remains watertight.
• We click the cap over the roof hook to give a neat finish.
• The mounting rails are fitted to the hooks and then the panels are fixed to the rails. The full mounting system is supplied by K2 Systems and is made in the UK.

This process ensures that the panels are securely attached to the home’s structure, not the fragile slate tiles, protecting the roof from any damage.

The Genius SpeedFlash system

At Agenda Electrical, we have a different approach to installing solar panels on slate roofs that is faster, safer, and more cost-effective for you. 

We use the innovative Genius SpeedFlash system, which provides a quick, no-drill method for installing solar panel brackets. This advanced system eliminates the need for traditional slate removal, speeding up the installation process and preserving your roof’s integrity.

Here’s why the Genius SpeedFlash system is a superior choice for your slate roof:

• No Slate Removal: The most significant advantage is the ability to install brackets and waterproof them without disturbing or removing any existing slates.
• Faster Installation: This “no-drill” method dramatically speeds up the process, often halving the time required for installation compared to traditional methods that involve slate removal. Using the SpeedFlash means we can now complete a slate roof as quickly and more efficiently than a concrete tiled roof.
• Maintains Roof Integrity: By avoiding slate removal and drilling, the SpeedFlash system prevents potential water ingress and maintains the structural integrity of the roof.
• Protects Slates During Installation: A special tool is included with the kit to allow our installers to cut the necessary slots for the hooks without damaging the surrounding slates or the ones underneath.
• Weathertight Finish: The system ensures a reliable and weatherproof finish, preventing light snow and water from getting under the roof slates.
• Minimises Risk and Cost: Reducing the number of disturbed slates lowers the risk of breakage, making the installation neater and more durable, and ensuring the installation is MCS 012 compliant.
• Ideal for Large Slates: The system is particularly effective on slate roofs with slates that are 18 inches or larger.
  
  

What Are the Costs and Considerations?

Yes, installing solar on a slate roof can typically be a little more expensive than a standard installation. By using SpeedFlash, installing on a slate roof is now roughly the same cost as a tiled roof.

For a 10 panels system on one elevation, including scaffolding:

Premium, all black German-designed Solarwatt panels, Solarwatt “in cooperation with BMW” inverter, K2 mounting system and stainless steel pin bird blocker –   £7,700 (No VAT on domestic solar and battery installations)

Standard, all black Trina panels with Solax inverter, K2 mounting system and no bird blocker £5,760 (No VAT on domestic solar and battery installations)

Important Considerations

• Historic or Listed Buildings: If your home is in a conservation area or is a listed building, you will likely need to obtain listed building consent or special planning permission before installation. Regulations are in place to preserve the aesthetic of such buildings. In these cases, it might be necessary to consider alternatives like ground-mounted solar systems or innovative, in-roof solar tiles that blend more seamlessly.
  
  

In Summary: A Worthwhile Investment

Installing solar panels on a slate roof is an excellent way to modernise your home and harness renewable energy without sacrificing the beauty or integrity of your roof. While it requires a specialised approach and a slightly higher initial investment, the long-term benefits in energy savings and increased home value make it a worthwhile project. The key to a successful installation is simple: choose the right expert for the job