Metal roof do not need roof conductor as lightning protection system?
Metal roof do not need roof conductor as lightning protection system?
(OP)
Hi mates,
need your advice on whethre is it possible to connect the down conductor to the metal roof directly and without installing any roof conductor.
because there are people having the idea that: metal roof could be the conductor which act as if air terminal and roof conductor. my understanding is that the metal roof is not good enough to carry the high ampere of lightning strike which could be penetrated and caused phisical damage on the metal roof sheet.
kindly enllighten me on this issue. even welcome shall there be any standards or theory/calculation that could clarify my doubt.
thanks.
loke
need your advice on whethre is it possible to connect the down conductor to the metal roof directly and without installing any roof conductor.
because there are people having the idea that: metal roof could be the conductor which act as if air terminal and roof conductor. my understanding is that the metal roof is not good enough to carry the high ampere of lightning strike which could be penetrated and caused phisical damage on the metal roof sheet.
kindly enllighten me on this issue. even welcome shall there be any standards or theory/calculation that could clarify my doubt.
thanks.
loke






RE: Metal roof do not need roof conductor as lightning protection system?
The steel or aluminum roof is probably a reasonably good conductor, but you must also consider how this roof is bonded to the rest of the building and to earth. I would expect significant side flash issues. It's always good to remember that you're dealing with an arc that traveled maybe 30,000 feet through the air - so our attempts to control it often fail.
RE: Metal roof do not need roof conductor as lightning protection system?
could see:
4.6.1.2 Metal parts of a structure that are exposed to direct lightning flashes and that have a metal thickness of 4.8 mm ( in.) or greater shall require only connection to the lightning protection system.
4.6.1.3 Such connections shall provide a minimum of two paths to ground.
RE: Metal roof do not need roof conductor as lightning protection system?