The short answer is no you don t have to ground a metal roof and you will incur no additional risk if you don t ground it in most circumstances.
Should a metal roof be grounded.
Wouldn t a grounded metal roof protect your home.
We elaborate further in this post.
In simple terms the answer is no.
Hazardous currents have a path to ground the massive buried copper network and grounding electrodes.
Further in a dry environment it might be necessary to water the grounding stakes to assure good contact with the surrounding soil.
Metal roofing is safe and you won t incur additional risks if you don t ground it in most circumstances.
Dry soil is an insulator.
It is important to have every vertical metal support beam grounded required in the building code with a metal building.
Do you need to have your metal roof grounded.
Metal conducts electricity but when you are dealing with a full roof a lightning strike would ground out through the rest of the structure without causing damage or harm to the interior.
If you plan on using metal roofing you may need to consider whether or not you need to ground that roofing like other metal equipment in construction.
By bonding the steel rebar you simply eliminate the difference in potential between the metal objects above the steel rebar and the steel rebar you are not forcing current to travel through it to find a path to ground.
What if lightning struck your roof.
Your metal roof is not grounded and thus lighting has no reason to strike it.
Likewise the electrical system needs to have a good active ground.
Some actual disadvantages to metal roofs.
You might choose to install a metal roof because they do not rot crack peel burn or blow off.
You have numerous options when it comes to re roofing your home including asphalt shingles concrete tiles and metal roof panels.
In general there s no need to unless it s mandated by your local building codes.
Experts say metal roofing systems aren t any more likely to be struck by lightning than other types of roofs.
It does not attract any extra attention from lightning and just like buildings constructed with traditional building materials any electricity from a lightning strike will will be safely transferred to the ground below so occupants will be unaffected.