What constitutes a firewall? I have heard that it has to withstand two hours of fire, which can be accomplished by two layers of sheetrock. How thick does this sheetrock need to be? What does UL have to say about it, if anything? I am thinking of situations when 300.21 in the NEC has to be complied with.
firewalls
- Thread starter Dan67
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- New Jersey
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- Journeyman Electrician
This should be covered under the building code and should be specifically outlined on the drawings by the building designer. Usually 2 hr rated walls have two layers of 5/8 rock on each side of the wall. But I wouldn't think that you could just slap some extra layers of rock on a common wall of attached units and make a firewall.
boater bill
Senior Member
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- Cape Coral, Fl.
Firewalls are determined in NFPA 101 Life safety code. there are methods of construction and details approved by UL available from fire stop manufacturers such as Hilti.
Hope that helps.
Hope that helps.
mdshunk
Senior Member
- Location
- Right here.
Firewalls are easy to pick out on a print, because they'll have an octagon note or similar stating what sort of assembly it is.
In existing work, that's a little tougher. If it's existing, and it quacks like a fire wall, I treat it like a fire wall. Sometimes, you'll see something like this stenciled on the wall, above the drop ceiling, letting you know what sort of assembly the wall might be:
In existing work, that's a little tougher. If it's existing, and it quacks like a fire wall, I treat it like a fire wall. Sometimes, you'll see something like this stenciled on the wall, above the drop ceiling, letting you know what sort of assembly the wall might be:
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