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Roof over a roof?

M

Mech

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Joined
Oct 30, 2009
Messages
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Location
Eastern PA
I remember reading something once about having a roof structure over top of another roof structure is a bad idea, and perhaps a building or fire code no-no. The solution was to cut holes in the lower roof so in case of a fire, the heat could be released once a hole was made in the upper roof by fire fighters. Does anyone know to what I am referring? Is there a code section on this?

I am under IBC 2009.

Thanks
 
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hmmmm.

If the space is less than 30" high it doesn't have to be accessible.

Sadly, I knew of a home where a "home inspector" who could not gain access told the buyer, peering thru a gable end vent thru a ladder, said, "It's got two roofs!" so you're better off!

What was not known was whether the structure, ( a dbl wide MH ) was capable of bearing the load.

Also featured was new siding and boxing. Realtor's listing said "New Construction!".

Caveat emptor!
 
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If the space is less than 30" high it doesn't have to be accessible.
Click to expand...
Jim: Do you recall what code section this is from? The new roof will be more than 30" above the old roof.

I am remembering some article or story about fire fighters who cut through the upper roof, without knowing there was a second roof below. And since the lower roof remained in tact, without holes, the heat continued to build up or something like that and some fire fighters lost their lives.
 
Not jim but here it is.

R807.1 Attic access. Buildings with combustible ceiling or

roof construction shall have an attic access opening to attic

areas that exceed 30 square feet (2.8 m2) and have a vertical

height of 30 inches (762 mm) or more.
 
My fault.....you posted in Commercial Blg codes...I just hit what's new and took it for granted it was residential...sorry!!!!
 
IBC 2006 probably the same in 2009

1209.2 Attic spaces. An opening not less than 20 inches by 30

inches (559 mmby 762 mm) shall be provided to any attic area

having a clear height of over 30 inches (762 mm). A 30-inch

(762 mm) minimum clear headroom in the attic space shall be

provided at or above the access opening.
 
I usually try to post the code I am referring to, and I forgot this time. D'oh! I edited the first thread to fix it.
 
Makes for a helluva combustible concealed space...and a helluva show in the night sky!
 
Thanks MT. That's the thread I was remembering. I searched the Fire code archive, not the Building code.
 
A three legged dog goes into a bar, the bar tender sez "get out! we don't allow dogs in hear". The dog sez I'm looking for the man who shot my

pa!"

"Roof" "Roof"

pc1
 
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