SprinklerDesigner2
Mechanical
- Nov 30, 2006
- 1,251
TABLE 17.2.3.1 ESFR Protection of Rack Storage Without Solid Shelves of Plastics Commodities Stored Up to and Including 25 ft (7.6 m) in Height. I am dealing with 25' rack storage of cartoned and exposed nonexpanded plastics.
I have a 200'x150' 30,000 sq ft 8" deep bent metal purlin/rigid metal frame building.
Span across peak is 200'-0". Roof pitch is the standard 1" in 12".
Eave height is 24'-0" which puts the peak at 34'-4" measured to the underside of the metal roof deck. Off the peak 1'-4" we have an 8" bent metal purlin and there is insulation which I might call 2".
That four inches (3 inches if you count half the insulation depth) is killing me! K16.8 pendents discharging at either 42 psi or 52 psi is a big deal on this job with pipe getting stupidly big and because of the water supply the 10 psi discharge pressure difference is costly.
It is something we've all done but I don't like installing 6" mains in a bent metal purlin building if I have any way around it.
With the 1" in 12" pitch once I get 3'-0" off the peak I'm good. Once I get to the first purlin off the peak I'm "short" just 1 1/2".
Ignore it pretending the peak is 32'-0"? Between just you and I I don't believe the two inches would cause the building to burn down but I just don't feel comfortable with ignoring something I know is there. If we were talking about just one inch I probably would ignore it.
Tell the owner to have the general contractor stuff another four inches of insulation just at the peak and two inches in the adjoining purlin space? I've seen them do this sort of thing in climate controlled buildings of the same construction type.
I have a 200'x150' 30,000 sq ft 8" deep bent metal purlin/rigid metal frame building.
Span across peak is 200'-0". Roof pitch is the standard 1" in 12".
Eave height is 24'-0" which puts the peak at 34'-4" measured to the underside of the metal roof deck. Off the peak 1'-4" we have an 8" bent metal purlin and there is insulation which I might call 2".
That four inches (3 inches if you count half the insulation depth) is killing me! K16.8 pendents discharging at either 42 psi or 52 psi is a big deal on this job with pipe getting stupidly big and because of the water supply the 10 psi discharge pressure difference is costly.
It is something we've all done but I don't like installing 6" mains in a bent metal purlin building if I have any way around it.
With the 1" in 12" pitch once I get 3'-0" off the peak I'm good. Once I get to the first purlin off the peak I'm "short" just 1 1/2".
Ignore it pretending the peak is 32'-0"? Between just you and I I don't believe the two inches would cause the building to burn down but I just don't feel comfortable with ignoring something I know is there. If we were talking about just one inch I probably would ignore it.
Tell the owner to have the general contractor stuff another four inches of insulation just at the peak and two inches in the adjoining purlin space? I've seen them do this sort of thing in climate controlled buildings of the same construction type.