Repair Garage

[volt101]

Ok, the code talks about repair garages in 511. The areas next to the service bay, in this case a showroom, what is an effective wall as stated:

511.A(3) Specific Areas Adjacent to Classified Locations - Areas adjacent to classified locations in which flammable vapors are not likely to be released, such as stock rooms, switchboard rooms, and other similar locations, shall not be classified where mechanically ventilated at a rate of four or more air changes per hour, or designed with positive air pressure, or where effectively cut off by walls or partitions.

Can this be a sheet rock wall, or will concrete be required?

The handbook has a picture (I know, not code!) that shows the door's sill to be not less then 18" above the hazardous location's floor. I can not find any wording in the code to support this. NFPA 30A either. The ICC 2000 IBC has wording that the wall must not have openings except for fire rated, self closing doors.

Writting contradictions.

 

[muskiedog]

Re: Repair Garage

Sheet rock should be adequate. As long as it is a solid wall that will not allow vapors to pass.

 

[rbalex]

Re: Repair Garage

Originally posted by volt101:
Ok, the code talks about repair garages in 511. The areas next to the service bay, in this case a showroom, what is an effective wall as stated:

511.A(3) Specific Areas Adjacent to Classified Locations - Areas adjacent to classified locations in which flammable vapors are not likely to be released, such as stock rooms, switchboard rooms, and other similar locations, shall not be classified where mechanically ventilated at a rate of four or more air changes per hour, or designed with positive air pressure, or where effectively cut off by walls or partitions.

Can this be a sheet rock wall, or will concrete be required?

Any generally non-porous, non-pierced, structurally sound material is ?effective? enough; i.e. sheet rock is fine.

The handbook has a picture (I know, not code!) that shows the door's sill to be not less then 18" above the hazardous location's floor. I can not find any wording in the code to support this. NFPA 30A either. The ICC 2000 IBC has wording that the wall must not have openings except for fire rated, self closing doors.

The 18? reference is simply the logical inference of 511.3(B)(1)

Writting contradictions.

[ June 17, 2005, 12:18 PM: Message edited by: rbalex ]

 

[volt101]

Re: Repair Garage

Just not too sure I like the idea of sheetrock. We are talking about a liquid gas spill (in this case) that might occur, hence Class I div II. "What If" a gas leak occured next to the sheet rock? The sheet rock's paper would wick the gas (ever see mold grow upwards on this stuff in the basements), also the fire rating of the rock would be compromised.

 

[iwire]

Re: Repair Garage

Volt I think Bob (rbalex) has written a few of these requirements, at the least he has been involved with the process.

From the sound of his reply the wall does not have to be fire rated only vapor proof.

 

[volt101]

Re: Repair Garage

ICC 200 IBC section 406.6.2 begs to differ.

 

[iwire]

Re: Repair Garage

Originally posted by volt101:
ICC 200 IBC section 406.6.2 begs to differ.

 

[rbalex]

Re: Repair Garage

In this case, only "involved with the process."

CMP14 gives a great deal of deference to the Automotive and Marine Service Station TC. They probably author 60-75% of Art 511 via material extracted from NFPA 30A.

Actually, my sheetrock response is based on fairly standard electrical area classification practices outlined in NFPA 497 and APR RP 500. The wall doesn't even necessarily need to be vaporproof, it just needs to inhibit the free flow of vapors from the classified location.

Even though I don?t generally like gas detectors as a protection technique, some of the concepts used to justify it as it relates to simple barriers are hinted at in 500.7(K)(2). FPN No 2 references RP 500 where other specific applications of walls as they relate to area classification boundaries are described. None of these standards generally specify a fire rating although other building codes certainly could. It just isn?t an NFPA or API issue.

 

[volt102]

Re: Repair Garage

To the two Bob's,

Thanks. I just wanted to know if it was an nfpa issue, 70 or 30a. I have read both and just wanted to be doubled checked.

Thanks again,

Jim