New metal roof on existing concrete garage

[Bullterrier]

Hello all, I need some advice please.

We have a detached concrete sectional garage that is one of a semi detached pair with our neighbour. The garage has power (via SWA off a fused spur within the house with earthing provided back to the TN-C-S supply). One double socket and a light via a 3amp spur. All has been tested and found to be fine. The garage has a metal up and over door that was not deemed to be an extraneous conductive part when the power was installed or when recently examined and tested as part of a periodic inspection.

The roof is currently cement board (corrugated with white asbestos) and the neighbour has damaged theirs such that it needs replacement.

The roof spans both garages so his insurer intends to replace both with powder coated profiled metal. A new non asbestos roof is a nice present.

The insurer plans no changes to the power provision as they state that the metal roof isn't in contact with the grounŷd and so is not an extraneous conductive part.

Given we currently have a fully happy periodic inspection in place for the whole house and garage I need to make sure they are correct and that we don't need the new roof bonding (10mm cable back to the meter point would be one heck of a task (it's on the other outside wall of the house and this is a mid terrace) so a TT spike solution would probably be needed).

Is a metal roof that a) connects to next door and b) isn't in contact with the ground an extraneous conductive part? If so, was the garage door already one? The guy who does our electrical work has just started his 3 week holiday in Florida, hence asking your learned selves here so we don't end up with a problem after the insurers' contractor leaves.

Thanks in advance....

 

[westward10]

If the new roof is "floatig" and has no direct contact to the ground then no, it doesn't need bonding.

 

[Bullterrier]

Thanks. Does that also apply to the up and over door?

 

[westward10]

The garage door doesn't need bonding.

 

[telectrix]

what he said. ^^^^^. fit and forget.

 

[Bullterrier]

That's good news - thanks. The house is rented and I like to keep squeaky clean.

 

[Michael4321.]

If garage door is outside must be connected to the Equipotential Ground and all metallic hand contact see the Law of Electrical Ground and Schematics Diagram for Earth Ground. Prevent Atmospheric Electrostatic also.

 

[DPG]

If garage door is outside must be connected to the Equipotential Ground and all metallic hand contact see the Law of Electrical Ground and Schematics Diagram for Earth Ground. Prevent Atmospheric Electrostatic also.

Maybe in Romania, but not here!

 

[Darkwood]

If garage door is outside must be connected to the Equipotential Ground and all metallic hand contact see the Law of Electrical Ground and Schematics Diagram for Earth Ground. Prevent Atmospheric Electrostatic also.

The Forum is based around the British Standards BS7671 and advice given should fall within these standards unless otherwise specified, I assume your own regulations differ to ours so please if giving advice make it clear which regulations you are citing your information. We of course welcome members from across the globe but heed caution when offering advice that you are not doing so in contradiction of our British Standards unless the thread or post has specifically asked for advice regarding other reg's.

 

[Pat H]

Just don't mention the Scottish...

 

[telectrix]

The Forum is based around the British Standards BS7671 and advice given should fall within these standards unless otherwise specified, I assume your own regulations differ to ours so please if giving advice make it clear which regulations you are citing your information. We of course welcome members from across the globe but heed caution when offering advice that you are not doing so in contradiction of our British Standards unless the thread or post has specifically asked for advice regarding other reg's.

maybe romania have just got the 15th.

 

[Deleted member 9648]

maybe romania have just got the 15th.

I believe Cockburns in charge out there.

 

[telectrix]

yep. i saw a Dacia taxi today. had a 3 ft. piece of 6mm Gn/Y hanging from the bumper.

 

[Deleted member 9648]

Thinking about it though I'd pay good money to watch someone bond an up and over garage door......

 

[telectrix]

easy peasy. a 10ft service loop in tri-rated 10mm.

 

[The Ghost]

The salient points here are that one; if the insurers state in writing that bonding is not needed then they will be liable for any damage or harm that arises from same
two; the landlord is responsible for the electrical safety of tenants and must satisfy himself this is true.
Perhaps ask the insurers to pay for a certificate to be issued regards the facts stated. After all they are insurers not electricians. With all due respect to opinions offered here, they will not cover you in the event of harm to property or person. For instance there is a greater risk of lightning damage now you have a metal roof.

 

[DPG]

The salient points here are that one; if the insurers state in writing that bonding is not needed then they will be liable for any damage or harm that arises from same
two; the landlord is responsible for the electrical safety of tenants and must satisfy himself this is true.
Perhaps ask the insurers to pay for a certificate to be issued regards the facts stated. After all they are insurers not electricians. With all due respect to opinions offered here, they will not cover you in the event of harm to property or person. For instance there is a greater risk of lightning damage now you have a metal roof.

There's an even greater chance of a lightning strike if it is earthed.

 

[westward10]

The salient points here are that one; if the insurers state in writing that bonding is not needed then they will be liable for any damage or harm that arises from same
two; the landlord is responsible for the electrical safety of tenants and must satisfy himself this is true.
Perhaps ask the insurers to pay for a certificate to be issued regards the facts stated. After all they are insurers not electricians. With all due respect to opinions offered here, they will not cover you in the event of harm to property or person. For instance there is a greater risk of lightning damage now you have a metal roof.

Having a metal roof does not increase the risk of lightning strike it will make no difference what so ever. It may actually protect the building by dissipating it over its large conductive area. Lightning seeks a path of least resistance to earth and an isolated metal roof will not draw its attention, it is more likely to go for the tall tree next to it. Lightning protection draws the charge from the building structure to earth by its lower resistance path, lightning protection and any associated attractors do not necessarily draw the lightning towards them it merely deflects it once it strikes. Main protective bonding to these parts is a recent requirement to stop the lightning being attracted to internal circuit protective conductors which can result in damage.

 

[static zap]

Up and over (the top) solution .

...... Prevent Atmospheric Electrostatic also.....

An ionising radioactive source , for a wireless solution ?
... for some where they just have the stuff laying around

( Any lightening worries -Get in the car )

 

[davesparks]

The pointy TV aerial strapped to the chimney will attract the lightning more than a metal roof covering with no particularly pointy bits.