2006 IBC Table 508.3.3

[alora]

I've been taught to use the above table a certain way. Generically meaning, for example, an "A" occupancy needs to have a 3-hour separation from an "H-3" occupancy if there are no sprinklers provided. This applies equally for "A"-to-"H3" as well as "H3"-to-"A". The em dashes in the remaining boxes do not imply that there are no separation requirements.

However, I was told by a plans examiner that the left column (up-down) is for the larger of 2 occupancies, with the upper row (left-right) for the smaller. He gave an example of of a 2,000sf "B" occupancy not needing any separation from a 1,800sf "S-2" occupancy.

From a life safety, common-sense standpoint, what I've been taught seems right. More so than what the plans examiner told me.

Anyone have any thoughts?

The only resource I found that backs up my understanding is the Code Commentary; however, it does so only by the facts provided in Example 1 (page 5-34).

 

[rktect 1]

The B and S-2 requires separation.

 

[alora]

Ok...

That wasn't the question though.

 

[vegas paul]

Your plans examiner needs a refresher course, and also needs to read the commentary...

 

[Paul Sweet]

The dashes are there because once upon a time printing errors made the rating different if you read vertical to horizontal than if you read horizontal to vertical.

Using his logic, a larger H-1 wouldn't need to be separated from a smaller A or E.

 

[georgia plans exam]

The dashes mean: try it the other way until you reach a 1,2,3,N or NP.

GPES

 

[peach]

Rather than making the table painfully long, the editors decided that we should be able to realize that the separation is the same whether they list it as H-3/A or A/H-3.

duh

 

[Francis Vineyard]

I've been taught to use the above table a certain way. Generically meaning, for example, an "A" occupancy needs to have a 3-hour separation from an "H-3" occupancy if there are no sprinklers provided. This applies equally for "A"-to-"H3" as well as "H3"-to-"A". The em dashes in the remaining boxes do not imply that there are no separation requirements.However, I was told by a plans examiner that the left column (up-down) is for the larger of 2 occupancies, with the upper row (left-right) for the smaller. He gave an example of of a 2,000sf "B" occupancy not needing any separation from a 1,800sf "S-2" occupancy.

From a life safety, common-sense standpoint, what I've been taught seems right. More so than what the plans examiner told me.

Anyone have any thoughts?

The only resource I found that backs up my understanding is the Code Commentary; however, it does so only by the facts provided in Example 1 (page 5-34).

Non-separated occupancies are very limited and the example given is not allowed using Table 508.2

508.3.3.4 Individual occupancies shall be separated from adjacent occupancies in accordance with Table 508.3.3.

Have the examiner explain where that line of reasoning is in the code.

 

[Gene Boecker]

VP is right. The plans reviewer needs a refresher course. Whoever was that instructor should be sent back to school.

There is no larger and smaller. If the option for separated mixed use is used (and that's an option since non-separated is also an option) then it's the separation between the two that matters.

This is no different from those "distance between" charts that are on those analog things called "maps."