With the ongoing power outages in South Africa, many households and businesses are resorting to solar energy. Solar panels are mostly installed on rooftops of residential buildings, factories, and warehouses. Roofing contractors are struggling to meet the growing demand for solar panel installations. It is of utmost importance that solar panels be installed by trained roofing contractors in Cape Town such as CTW Construction Group and Asbestos Removal and Roofing. 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.
Furthermore, it is illegal to remove, transport or dispose of asbestos, unless it is done by a registered asbestos contractor.
There are certain roof limitations when it comes to installing solar panels. With the variety of roof materials found in South Africa it is very important to consider the type of roof material present before embarking on installing solar panels. While it is safe to install solar panels to metal sheeting, concrete slabs (RCC) and most types of tiles, it is not safe to install solar panels on roofs containing asbestos.
Most asbestos cement roofs are over 40 years old. To clean and maintain these roofs can be dangerous, not to mention installing solar systems on them. Of all asbestos building materials, roof sheeting is usually in the poorest condition as it is directly exposed to sun, wind, rain and hail, and often damaged by moss and lichen that grows on its surface. To seal or coat a product the surface first needs to be safely cleaned and this may be virtually impossible for roofs that have not been maintained over time and/or that have significant moss and algal growth penetrating the surface
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.
Building or homeowners need to know that any form of power tool or pressure cleaner is prohibited to be used to clean or repair an asbestos cement roof. Use of these can lead to exposure of fibres and contaminate the property and surrounding properties. Asbestos contamination spreading from any damage can lead to high clean-up costs, which may not be covered by household insurance.
Reasons why a solar power system should not be installed on asbestos roofs.
As mentioned, with age asbestos becomes brittle and can easily crack or break under the load of a rooftop solar system.
The loadbearing capacity of asbestos is not as high as it is for other roof types such, as metal sheeting, tiles, or concrete. Under the effect of the static load (the actual weight of the system), and the dynamic load, (the weight of the installation agents and maintenance teams), old asbestos roofs could collapse, or the sheets will most likely develop cracks.
Cracks will allow moisture and water to seep into the building. This type of water ingress could cause a variety of problems such as:
- Compromise of the structural strength of the building when steel mounting structures and concrete reinforcement starts rusting or corroding.
- Could cause electrical wiring to be compromised.
- Damage to contents of the building.
- Mold, damp, and humidity – posing health risks.
Preparation of an asbestos roof for solar panel installation
According to the South African Asbestos Abatement Regulations of 2020 only an asbestos contractor registered with the Chief Inspector (Department of Employment and Labour), is permitted to remove, or prepare asbestos surfaces.
Acquiring roofing contractors that are also asbestos experts is highly recommended when planning on installing a solar system on an asbestos roof.
Also read: 7 Simple and Crucial Tips to Renovate Your House
