table 508.4 - why is F-2(low) protected from S-1, but F-1(moderate) is not?

[Keith]

In Table 508.4 the F1 occupancy has no separation requirement with S-1,

but F-2 is 1 hour.

Why is an F-1:MODERATE hazard less restrictive with S-1

than the F-2:LOW hazard with S-1?

thanks

 

[Coug Dad]

Welcome to the board. F1 and S1 are considered about the same hazard. You are protecting the lower hazard F2 from the S1, not the other way.

 

[rktect 1]

Backwards thinking. Like coug dad said.

 

[righter101]

sdrawkcaB

I had this same question when I was reviewing some mixed use buildings.

If you have B occupancy, it needs to be separated from a S2 (low hazard storage) with a 2 hour separation.

Increase the hazard of the storage to an S1, (moderate hazard) and voila, no separation required.

Seems counterintuitive to me. Increase the hazard, eliminate the required separation

 

[brudgers]

I had this same question when I was reviewing some mixed use buildings.If you have B occupancy, it needs to be separated from a S2 (low hazard storage) with a 2 hour separation.

Increase the hazard of the storage to an S1, (moderate hazard) and voila, no separation required.

Seems counterintuitive to me. Increase the hazard, eliminate the required separation

That code provision doesn't exist in a vacuum. Construction type also plays a role in limiting the size of each occupancy - and there are thresholds for sprinklers as well.