Suitable Roofing Materials for Solar Panel Installations
Not Suitable for Solar Panel Installation
1. Asbestos Roofs: In a letter from the Department of Employment and Labour, dated 11 November 2022, Departmental Inspectors have been instructed to not allow asbestos work that entails the installation of any solar panels or sheets onto existing asbestos roofs.
As asbestos roofs age they weaken, leading to the potential for breakage and even collapse. Furthermore, as the cement matrix breaks down, asbestos fibres are released into the air or washed into the gutters. Gutter waste can become contaminated and needs to be safely removed and disposed of.
Asbestos Removal and Roofing offers a full roofing service that includes safe removal of asbestos, re-roofing and solar panel installations.
2. Timber tile roofs are not recommended for solar installations. It presents a high fire hazard, and timber tiles are fragile and can easily crumble during installation.
3. Thatched roofs are not suitable for solar panels. There’s no mounting system designed for thatch, which wouldn’t be ventilated well enough underneath the panels and so would rot. Given that thatched roofs already present a fire risk, putting an electrical system on top wouldn’t be sensible.
Suitable but not recommended for Solar Panel Installation
Tin roofs:
Tin roofs are not as common today as they were 150 years ago. You can still purchase tin roofing, although it’s not as easy to find as corrugated metal, aluminium, and steel. Most tin roofs tend to be older and rusty, and are likely to sustain damage from installers standing on them, screwing in racking, or the weight of panels. It is advisable to have a professional roofing contractor in Cape Town inspect whether it is stable enough for a solar installation.
Old Brittle Terracotta Tiles:
Brittle Terracotta clay tiles on a roof may run the risk of cracking or breaking during an installation. Your solar panel installer will be able to point out potential damage, risks and solutions.
Decramastic tiles:
These pressed metal tiles (also known as Decrabond) were popular in the 70s and 80s. They were made of aluminium or galvanised steel, and featured either a painted finish or a bitumen coating to allow a stone finish. Decramastic tiles can usually be identified by the fact there is no separation between the tiles horizontally or vertically.
When installing solar, these tiles can easily be dented or damaged, causing leakage and structural issues. They may also have an asbestos finish, which makes it illegal for solar installers to install solar panels onto this type of roofing.
Most Suitable Roofing Materials for Solar Panels?
Although most roofs are suitable for solar installations, metal sheeting and composite shingles are the two most popular and suitable roofing materials on which to install solar panels.
Metal, Klip Lock Roofs:
Primarily used for commercial premises, flat or Klip Lock roofs offer ease of installation for solar installers. The flat surface makes roof work easier, and mounting brackets can grip the ribs in the roof sheets. The only difference from a standard angled roof is that the flat surface may require tilt frames to get the optimal solar efficiency for your system.
Composite shingles:
Composite shingles are often the most affordable residential roofing type and excellent roofing material on which to install solar panels. Because composite shingles are so common, this roof type offers the widest range of options for equipment and installers. This reduces the need for specialised solar equipment and labour, and reduce your overall project costs.
Some other roof types such as clay and slate tiles will cost more in terms of preparation or repairs, which can lower the return on investment of your new solar system, and in some cases, increase the risk of damage to your roof in the long term.
It is advisable to have a qualified solar installer and roofing contractor to inspect your roof, so that they can provide the best advice on the quality of your roof and the risks associated with installing solar panels.