We don’t often think about the roof on our home, let alone venture up there. We simply let it get on with its job, protecting us from the elements year after year.
You may be vaguely aware of the type of roof tiles that are sheltering you from the weather, but the question takes on more importance if you want to get solar panels in the UK and you actually have slate tiles on your roof. So can solar panels be added to a slate roof?
Potential Problems of Installing Solar Panels on a Slate Roof
Solar panels can be installed on slate roof tiles but it can be more difficult than a standard tiled roof. Specific considerations need to be taken into account, especially with older slate roofs, and these include:
- Roof condition. A slate roof can usually last up to 200 years but needs regular maintenance to keep it in good condition.
- Tile fragility. While slate tiles are strong and highly resistant to the effects of extreme weather, they’re still a relatively brittle roofing material.
- Potential damage. Stepping on slate roof tiles without care can damage them, as can other types of impact.
- Weight. Slate is heavier than some other types of roofing materials.
These considerations can make installing solar panels on a slate roof problematic, but in most cases the issues can usually be overcome.
How to Avoid Damage When Installing Solar Panels on a Slate Roof
If you have a slate roof, solar panels need to be installed to professional standards taking into account extra precautions. These are necessary due to the unique characteristics of slate as a roofing material.
The main problem is potential damage to the roof, bearing in mind that slate tiles are one of the most expensive roofing materials. The following precautions will help protect your slate roof when installing solar panels.
Ensure the Roof Is in Good Condition
If your slate roof is in poor repair because of lack of maintenance over the years, it won’t be suitable for solar panels. As slate tiles age, thin flakes break off from the surface. This makes them increasingly soft and spongy.
Solar panel installation on a roof with weak spots will make the problem worse. If your slate roof needs repairs, a good time to have the job done is before installing solar panels.
Minimise Tile Damage
Working on a slate roof is challenging. The brittle nature of the tiles means it’s possible some will break when fitting solar panels.
However, a professional installation will minimise damage. For example, experienced solar installers will avoid drilling directly into the slates, which could compromise their structural integrity.
They’ll also replace any tiles that are otherwise damaged during the installation, ensuring your roof is restored as near to its original condition.
Calculate Solar Array Weight
Slate roof tiles weigh around 8-10lbs (3.6-4.5kg) a square foot. Rooftop solar installations weigh 40-45lbs (18.1-20.4kg) per panel, plus there’s the extra weight of mounting equipment to take into account.
The weight of the solar array needs to be carefully calculated into the installation process. This ensures no damage is caused to the roof structure.
Slate roofs are usually strong enough to support the weight of solar panels. However, sometimes a roof’s load-bearing capacity may need to be reinforced to take the extra weight.
Use Special Equipment
Specialised mounting equipment is required when installing solar panels on fragile slate tiles. This avoids or minimises damage to the roof and ensures a secure, long-lasting installation.
Furthermore, the right type of sealants and flashing are important to ensure waterproofing without damaging the tiles.
The Process of Installing Solar Panels on a Slate Roof
Installing rooftop solar panels is a multi-step process. Professionals have the training and experience crucial to minimise or avoid damage to slate tiles during each stage.
The installation process includes:
- Marking out where the solar array will be located.
- Removal of nails holding the tiles in place.
- Removing tiles and fixing anchors to the roof battens.
- Fixing waterproof flashing over the anchors.
- Cutting removed tiles to size and replacing them around the anchor and flashing.
- Attaching rails to the roof anchors.
- Mounting the solar panels onto the rails.
- Installing flashing to protect cables.
Maintenance of Solar Panels on a Slate Roof
Solar panels on a slate roof typically last as long as those on other types of roofs – 25 to 30 years.However, layers of dirt, dust and bird droppings make solar panels less efficient by impairing light absorption.
Rainfall will wash away much of the grime, but sometimes it washes it into the corners of the panels. This causes the panels to heat up, which also reduces efficiency.
A thorough cleaning every few years will get the most out of your solar panels. This entails switching off the system to avoid risk of electric shock.
Working on a fragile roof surface such as slate tiling requires specialised safety equipment. Unless you have it and are experienced in rooftop work, cleaning your solar panels is best left to professionals. This also avoids damage that could invalidate your solar installation warranty.
Cost of Installing Solar Panels on a Slate Roof
The cost of installing solar panels on any type of roof depends on factors such as the type of panels and size of the system.
Installing solar panels on slate roof tiles generally costs more than with other types of roofing materials. This is largely because the job takes more time, the installation process is more involved and labour intensive, and slate tiles need to be handled with extreme care.
Costs can range anywhere from £50 to £150 a panel. This means the price of installing a solar array on a slate roof is likely to start from around £5,000.
Advantages of Installing Solar Panels on a Slate Roof
Concrete tiles are the most prevalent roofing material in the UK, but slate roof tiles are also commonplace. They’ve been around for centuries and are still popular today because of their impressive lifespan.
Although expensive, slate tiles are an environmentally-friendly roofing material that can be recycled.Solar panels likewise reduce your carbon footprint, so installing them on a slate roof can be a good fit if you’re concerned about environmental damage and climate change.
Slate tiles are also aesthetically appealing, and the similar colours and shades of solar panels can blend in with them without disrupting visual appeal.
A further advantage of installing solar panels on a slate roof is reducing reliance on the electricity grid to power your home. Solar panels can cut your electricity bills by up to 70%, and even more when combined with solar battery storage.
Is Your Slate Roof Suitable for Solar Panels?
Effective Home has been installing solar panels on all types of roofs across the UK for more than 15 years.
We offer free, no-obligation site surveys that can help you decide whether your slate roof is suitable for solar panels.
Contact us online or call 0333 003 0703.
Making Solar Panels More Affordable
If you’re concerned about the extra cost of installing solar panels on your slate roof, Effective Home can help with this too.
We offer financing so you can spread the cost of going solar. And we can help you find out whether you’re eligible for a government grant that could cover most or all of the cost of solar panel installation.
Furthermore, there’s no VAT on professional solar energy installations until March 2027, so there probably hasn;t been a better time to make the move to solar power.
