Hi All

We are having a problem with electricians providing a quote to CoC our holiday home.

It is a thatched roof and some of the wiring runs close to the thatch without being in conduit. This must obviously be remedied but the difference in opinion on how is about R40 000 worth.

All or most of the wiring is twin flex. One guy wants to rip all the house wiring out and replace with Surfex   the other wants to just encase all the twin flex in conduits, and one in between with some Surfex and some conducting.

Is there a definitive specification in the regulations for thatched roof house wiring and where do I access this please.

Will eventually be going solar, with the panels on top of the water tower and car port, but for now it the CoC problem.

2 hours ago, George Christian said:

Is there a definitive specification in the regulations for thatched roof house wiring and where do I access this please.

I assume there is no special requirements for thatched roof houses. That being the case, your least expensive option would probably be putting in the usual plastic conduits and feeding the existing wiring though those (copper has become seriously expensive). Assumption is that wiring is sized correctly and protected by circuit breakers of appropriate rating. I assume your twin flex wiring is for lighting and as far as I am aware this does not require earthing, but someone who is a qualified electrician may want to comment on this. All 5/15A plug sockets MUST have an earth connection so that the earth leakage trip switch/ground fault interrupter can do its thing if things go wrong.

If you can tackle the conduit installation yourself, you can probably save a bundle and if you don't have to replace any or much copper, even better.

13 minutes ago, Kalahari Meerkat said:

I assume there is no special requirements for thatched roof houses. That being the case, your least expensive option would probably be putting in the usual plastic conduits and feeding the existing wiring though those (copper has become seriously expensive). Assumption is that wiring is sized correctly and protected by circuit breakers of appropriate rating. I assume your twin flex wiring is for lighting and as far as I am aware this does not require earthing, but someone who is a qualified electrician may want to comment on this. All 5/15A plug sockets MUST have an earth connection so that the earth leakage trip switch/ground fault interrupter can do its thing if things go wrong.

If you can tackle the conduit installation yourself, you can probably save a bundle and if you don't have to replace any or much copper, even better.

I dont know about plastic conduit. I would be worried. I would go for the metal ones personally but I am a bit paranoid about thatched roofs.

But yeah, if the wiring is sized correctly, breaker has the right ratings. One should theoretically be fine.

5 minutes ago, Denns said:

I dont know about plastic conduit. I would be worried. I would go for the metal ones personally but I am a bit paranoid about thatched roofs.

Yes/No, if the wires haven't run hot up to now and started a fire and the sizing is correct, then they should not start melting in the conduit and cause a fire either, I would personally consider metal as well, but, pricing and is it really necessary? Back in the day, well into last century it was metal conduiting by default and PVC wasn't even available until, I'm guessing the '70's or early '80's, but nowadays, the default is PVC and that is it...
I'd be much more worried about lightning protection, which is more likely to cause the thatch roof to start smoking...

Just now, Kalahari Meerkat said:

Yes/No, if the wires haven't run hot up to now and started a fire and the sizing is correct, then they should not start melting in the conduit and cause a fire either, I would personally consider metal as well, but, pricing and is it really necessary? Back in the day, well into last century it was metal conduiting by default and PVC wasn't even available until, I'm guessing the '70's or early '80's, but nowadays, the default is PVC and that is it...
I'd be much more worried about lightning protection, which is more likely to cause the thatch roof to start smoking...

I agree, but I am more concerned about what happens when it ages and the insulation begins to degrade. Obviously, your protection should take care of that scenario.

I do agree, though it would be an overdesign of the system to use metal conduit.

"One guy wants to rip all the house wiring out and replace with Surfex"

^^^THIS. (Surfix/Norsk)

Yip, both contractors were more worried about the lightning conduction , which, by the way needs it's own CoC ,

Needs to have less than 10 ohms from the base of the conductor to two test earth spikes at 6 and 12 meters away. AND a phat big 16mm sq copper cable running back to the DB. Its apparently a big bone of contention in the industry as to why you would want to route all that lightning voltage back to your DB and hence potentially every appliance plugged in

Wire mesh on roof must also be earthed.

All plastic conduit and trunking sold through bonifide distributors has to be flame retardant and metal piping has to be earth strapped and is a bitch for DIY work, so plastic it's going to be.

DB must also now have a surge/ arrestor and double pole earth leakage .

20 minutes ago, George Christian said:

DB must also now have a surge/ arrestor and double pole earth leakage .

I feel every house should have an SPD installed. Plenty of people are blowing their inverters when power is returned after an outage. I dont understand why you would not have an SPD when it costs 300 rand in this day and age.

32 minutes ago, Denns said:

I feel every house should have an SPD installed. Plenty of people are blowing their inverters when power is returned after an outage. I dont understand why you would not have an SPD when it costs 300 rand in this day and age.

Agreed. The cost of an SPD and even having it fitted by an electrician, is going to be less than the cost of fixing stuff that got damaged by a surge.

Some insurers will take the presence of a properly installed SPD into account and reduce your premium or excess. Or may refuse to honour claims attributed to a surge if you don't have an SPD installed in your DB by an electrician. They are not interested in the plug in devices that you can buy at Builder's. They want an SPD in the DB, and that to be shown on the COC.

No problems with the SPD at all, if it needs it, it must go in, and I'll check on my JHB house as well, I don't recall one .

My original bitch remains, no crystal clear regulations on wiring for thatch roofed houses, unless someone out there can enlighten me.

Thanks for all the help so far.

Edited November 28, 2025Nov 28 by George Christian

10 minutes ago, George Christian said:

No problems with the SPD at all, if it needs it, it must go in, and I'll check on my JHB house as well, I don't recall one .

SPDs are not mandatory, but they are a good idea.

During load shedding some insurers added wording to the effect that claims for damages due to power surge would be denied or would have an increased excess unless there was an SPD, in the DB, installed by a qualified electrician. They were not interested in the plug in items. Even now you may get a lowered excess or a reduced premium.

3 hours ago, George Christian said:

My original bitch remains, no crystal clear regulations on wiring for thatch roofed houses, unless someone out there can enlighten me.

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 hazard”. This part of IEC 62305 deals with the protection, in and around a structure, against physical damage and injury to living beings due to touch and step voltages. The main and most effective measure for protection of thatch 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 is intended to:

1. intercept a lightning flash to the structure (with an air-termination system),

2. conduct the lightning current safely towards earth (using a down-conductor system),

3. 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. And class1 spd's must be fitted between the point of controll and main earth electrode at the incoming supply cable.

I quote George:

"My original bitch remains" ......

"All or most of the wiring is twin flex"

To me, twin flex (ripcord) is for audio applications.

OK OK, you are dealing with a 5volt engineer here, and a Soutie to boot, so go easy on me. I am on the forum to learn  and bitch a bit and in learning, make sure that I am not being screwed over by circus providers, sorry service providers..

So, its Surfix, not Surfex, or god forbid Norsk and not Norse, and its Flat Twin and earth and not Flex and earth.

 Anyway, the COC is happening next week and all shall be revealed.

Once its properly ours, a battery back up will follow in the form of a 48volt Hybrid, sans panels for a while, watch this space.

Uploading Attachment...

Edited November 28, 2025Nov 28 by George Christian

1 hour ago, George Christian said:

So, its Surfix, not Surfex, or god forbid Norsk and not Norse, and its Flat Twin and earth

Surfix is such an elegant design for protection and shielding... But then we call twin and earth flat Surfix. Stick with round Surfix.

On 2025/11/28 at 4:05 PM, George Christian said:

OK OK, you are dealing with a 5volt engineer here, and a Soutie to boot, so go easy on me. I am on the forum to learn  and bitch a bit and in learning, make sure that I am not being screwed over by circus providers, sorry service providers..

So, its Surfix, not Surfex, or god forbid Norsk and not Norse, and its Flat Twin and earth and not Flex and earth.

 Anyway, the COC is happening next week and all shall be revealed.

Once its properly ours, a battery back up will follow in the form of a 48volt Hybrid, sans panels for a while, watch this space.

Uploading Attachment...

....and Soutie, what happened?

Watching this space for a long time.😄 (2 months)

Just my opinion on the matter. I know this is an old post, but maybe someone will still find it useful.

Using twin flex for fixed wiring is a definite no-no. Firstly, yes, the fitting must be earthed. While the lighting circuit doesn't necessarily have to be on an earth leakage breaker (that's a completely different scenario), the earth connection itself is mandatory.

Secondly, twin flex generally lacks the correct insulation ratings and approvals for fixed 230V AC wiring. It is typically designed for low-voltage DC applications like speakers or 12V LED lights.

Thirdly, the wire gauge is almost never correctly sized for the circuit breaker. Because the wire is too thin for a standard breaker, a fault will cause the flex to burn long before the breaker ever trips.

So, yes, the wiring must be replaced. Simply running the twin flex through a conduit will not solve the safety or compliance issues.

On the topic of the surge arrestor: no, it is not strictly a legal requirement for a standard setup (though it is always highly advised). However, if you are going for solar and installing a reputable brand, they WILL require surge protection to validate the warranty, and most insurance companies will mandate it as well."

Ask your insurance company what they require and then fit it.

Outsurance informed me that a 40KA SPD must be attached on main incoming line otherwise they will not cover elec surges.

I also fitted on my other DBs..R7k later!