3 Effective Thatch Roofs and Lightning Regulations to Keep You Safe
Did you know, Regulations for Effective Lightning Conductors on Thatch Roofs Save Lives
Thatch roofs are most susceptible than any other roof type to being set alight by lightning. For the protection of the public and property the South African National Standard 62305-3 was introduced in 2011.
SANS 62305-3: Protection against Lightning (published in 2011) is drawn from an international standard, IEC 62305. Part 3 deals with physical damage to structures and life hazards. It is 100% relevant to buildings with thatch roofs.
Remember that anything related to electrics must be dealt with by a qualified and registered electrician.
Introduction to the Regulations for Thatch Roofs and Lightning
This part of IEC 62305 deals with the protection, in and around a structure, against physical damage and injury to humans and living creatures who might touch or step on voltages.
The main and most effective measure for the protection of thatch roof structures against physical damage is considered to be the lightning protection system (LPS). This usually consists of both external and internal lightning protection systems.
An external LPS on thatch roofs is intended to:
- intercept a lightning flash to the structure (with an air-termination system),
- conduct the lightning current safely towards earth (using a down-conductor system),
- disperse the lightning current into the earth (using an earth-termination system).
An internal LPS prevents dangerous sparking within the structure using either equipotential bonding or a separation distance (and electrical insulation) between the external LPS components and other electrically conducting elements internal to the structure of the thatch roofs.
The main protection measures against injury to living beings due to touch and step voltages are intended to reduce the:
- dangerous current flowing through bodies by insulating exposed conductive parts, and/or by increasing the surface soil resistivity,
- occurrence of dangerous touch and step voltages by physical restrictions and/or warning notices.
The type and location of an LPS should be carefully considered in the initial design of a new structure, thereby enabling maximum advantage to be taken of the electrically conductive parts of the structure. By doing so, the design and construction of an integrated installation is made easier, the overall aesthetic aspects can be improved, and the effectiveness of the LPS can be increased at minimum cost and effort.
Once construction work on a site has started, access to the ground and the proper use of foundation steelwork for the purpose of forming an effective earth termination may well be impossible. Therefore, it is important to consider resistivity and the nature of the earth at the earliest possible stage of any project. This information is fundamental to the design of an earth-termination system and may influence the foundation design work for the structure.
Regular consultation between LPS designers and installers, architects, and builders is essential in order to achieve the best result at a minimal cost.
If lightning protection is to be added to an existing structure, every effort should be made to ensure that it conforms to the principles of SANS 62305-3. The design of the type and location of an LPS should take into account the features of the existing structure.
Notations
NOTE 1
Specific requirements for an LPS in structures dangerous to their surroundings due to the risk of explosion are under consideration. Additional information is provided in Annex D for use in the interim.
NOTE 2
This part of IEC 62305 is not intended to provide protection against failures of electrical and electronic systems due to overvoltages. Specific requirements for such cases are provided in IEC 62305-4.
NOTE 3
Specific requirements for protection against lightning of wind turbines are reported in IEC 61400-24 [2].
References
The following referenced documents are indispensable for the application of this national standard. These references are listed in the standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 60079-10-1:2008, Explosive atmospheres – Part 10-1: Classification of areas – Explosive gas atmospheres
IEC 60079-10-2:2009, Explosive atmospheres – Part 10-2: Classification of areas – Combustible dust atmospheres
IEC 60079-14:2007, Explosive atmospheres – Part 14: Electrical installations design, selection, and erection
IEC 61557-4, Electrical safety in low-voltage distribution systems up to 1 000 V a.c. and 1 500 V d.c. – Equipment for testing, measuring, or monitoring of protective measures – Part 4: Resistance of earth connection and equipotential bonding
IEC 61643-1, Low-voltage surge protective devices – Part 1: Surge protective devices connected to low-voltage power distribution systems – Requirements and tests
IEC 61643-21, Low-voltage surge protective devices – Part 21: Surge protective devices connected to telecommunications and signaling networks – Performance requirements and testing methods
IEC 62305-1, Protection against lightning – Part 1: General principles IEC 62305-2, Protection against lightning – Part 2: Risk management
We have a lightning conductor with a slight bend in it. How much of a problem does that pose for insurance?
Has there been any amendments to the law since 2018 regarding the earthing system?
Thank you
Since these regs are from 2011 they don’t, though it is in your interests to ensure the house is safe.
All lapas closed or open need plans. If no lightnig pole you wont get insurance
How do these new regulations apply to an existing house (more than 25 years old) that has a treated thatch roof?
A lapa is usually open-sided so might not require plans. A thatched roofed room is a structure that WILL require plans.
can lapa be fully enclosed by plastered walls with windows and doors? what is the difference between lapa and thatch roofed room?
Your problem is that the beam and truss requirements for the two types of roof are different. Maybe contact the manufacturers of Chromadek for contractor references.
Hi , just wondering if you ever did this conversion ? I want to do the same but can’t find anyone who has successfully done this . Are there any reputable roofing contractors that will even take it on ..? I want to convert from thatch to chromadek corrugated using the existing beams , would you have any advise ?
Brent, SANS 10313, 2010: Protection against lightning – Physical damage to structures and life hazard, discusses lightning protection systems (LPS). This standard defines an LPS designer as “a
person who is competent to design, construct and test the LPS for compliance with this standard”; and an LPS installer as “a person who is competent to install, construct and test an LPS for compliance with this standard”. This means the person must be trained and qualified to either design, construct and test and/or install, contract and test an LPS. So a thatch builder might be able to IF he has the qualification. It’s like asking if a building contractor is allowed to install electrics and/or plumbing. The answer would be only if the contractor is a qualified and registered electrician and/or plumber (which is not the norm).

Brent unfortunately we are not in a position to recommend companies.
What grass?
electrical connections have to be a meter from the grass unless it is fire proof equipment<<<<<<please comment if that is correct
Hi, I am looking for installers of LPS in Pretoria. Due to a leaking roof I had to redesign and replace my entire thatch roof. However, the builder removed my existing LPS and has now indicated that he is unable to replace it as he is not qualified to install the system. are thatch builders allowed to do this?
Hi,
I was recently forced to renovate and rebuilt my thatch roof as the previous owners severely neglected the roof. The current builder was asked to remove my LPS and to place it somewhere else on the property. He has now claimed ignorance and left me without a LPS on my property. Please direct me towards Pretoria based companies who can assist with the installation of the LPS at my property as 95% of the actual house is still thatch.
SANS 10407 deals with “Thatch Roof Construction” and any thatch roof has to comply with these standards. The roof needs to be designed by a “competent person”, the construction needs to be inspected by this person and if the roof meets the standards and is constructed correctly then they will issue a COC (Certificate of Compliance) and this would have been supplied to the local council building inspector before they issue an occupation certificate.
Subject:
SANS 10407
Message:
Hi,
Please could you advise me on the form that the structural engineer
must sign off (the entire process to bring the certificate to
conclusion) in terms of SANS 10407, the purchaser of the property was
very specific on the SANS 10407 certificate and report.
Any help will be greatly appreciated.
Kind Regards,
Bianca Scott
In House Legal Counsel
Read our post: boundary-lines-walls-fences But note that each municipality has a zoning scheme for each suburb and each property will be different. Check with your local planning department.