ROOFING
an“ oven effect”, increasing temperatures within the thatch and making the fire more aggressive and difficult to control.
Operational experience has shown that fires beneath tiled or sheeted thatch can be especially dangerous and challenging to extinguish. Over-covering therefore cannot be recommended as a fire-safety or engineering solution.
Fires beneath tiled or sheeted thatch can be especially dangerous.
Structural and maintenance issues
The additional load imposed by a new covering may affect the stability of the existing roof structure. Concrete tiles are significantly heavier than thatch, and most thatch pole structures are not designed to support them. Installation could result in structural failure unless the roof is reinforced or the rafters are rebuilt.
Future maintenance operations also become difficult and expensive because the oversheeting may have to be removed to repair leaks or address problems in the original thatch layer.
Lightweight corrugated or other roll-formed profile sheeting presents different concerns. It can be damaged if walked on during maintenance and may be vulnerable to extreme weather such as hail.
Insurance concerns
Many insurers may continue to classify the building as having a thatched roof while combustible material remains beneath the new covering. The building owner may therefore receive no reduction in premiums, while installing over-sheeting without approval could affect the insurance cover and claims.
Insurers may also consider the resulting fire damage likely to be more severe, affecting both the contents and the structure.
Regulatory compliance
Statutory building compliance is an important consideration for insurers. Compliance is demonstrated through approved drawings and supporting documentation, and modifications of this nature may require a professional fire-safety assessment and updated building plans.
Failure to comply with the National Building Regulations and the applicable provisions of SANS 10400 could affect the approval of the work and any subsequent insurance claim.
SANS 10407 applies alongside the relevant provisions of the National Building Regulations and SANS 10400. It addresses the design of supporting structures and the installation of conventional thatch roofing.
TASA distances itself from the practice of over-covering a thatched roof erected in accordance with SANS 10407 and signed off by a competent professional.
By following the relevant standards and using appropriate fire-safety systems, owners can enjoy the character, sustainability, and safety offered by a roof made from renewable material. Where fireretardant treatment is required, only suitably tested products that meet SANS 10400-T, Clause 4.12.2, should be used.
Fire safety is not limited to the roof. In rural areas, vegetation around buildings must be properly managed. In urban areas, the prescribed distances from boundaries and between neighbouring structures must be observed. Chimneys and fireplaces must be constructed correctly, while electrical cabling and other conductors must not come into contact with the thatch layer.
After
The photos show a roof where existing thatch has been completely removed and replaced with other materials. TASA argues that this is a preferable approach to over-roofing.
Contact TASA on 083 283 8429 or visit www. sa-thatchers. co. za
86 spring 2026 | www. tobuild. co. za