Common Entry

[Robert]

Attached (I hope) is a common entry to a B and R-3 occupancy, unsprinklered. Since the B is a higher hazard then the R-3, does wall #1 need the 2 hour separation from the common entry (exit access)? Or can I make wall #2 the 2 hour separation instead? Or would both need the 2 hour separation? Thank you. Thanks!

 

[cda]

I am thinking Either one

 

[RLGA]

Either, if you're using the separated occupancies method. However, if the area of the entire building does not exceed the allowable area for a Group B occupancy per the construction type, then the nonseparated occupancies method can be used and only a 1-hour fire partition is required between the Group R-3 and the Group B, and, in that case, Wall #2 would be the fire partition.

 

[RLGA]

Further, if the separated occupancies method is used, and Wall #1 was made the 2-hour fire barrier, then Wall #2 would still have to be a 1-hour fire partition; but, if Wall #2 was the 2-hour fire barrier, then Wall #1 would not require any fire rating.

 

[Robert]

Thank you. The # of stories of the building (3) exceeds the allowable for the B occupancy (2), so I must use separated occupancy method. Ron, I am enjoying your book btw!

 

[RLGA]

Thank you. The # of stories of the building (3) exceeds the allowable for the B occupancy (2), so I must use separated occupancy method. Ron, I am enjoying your book btw!

Thanks.

There are other options to look at, but some assumptions I want to confirm first before offering any include:

• The building is sprinklered per NFPA 13R (you can't have an unsprinklered building with a Group R occupancy).
• The construction type is VB.
• Stories 2 and 3 are part of the Group R-3 and there are no Group B occupancies on those stories.

Please correct me if I'm wrong on any of the above.

 

[cda]

So

What is the R-3???

And

Is it existing??

• Buildings that do not contain more than two dwelling units
  
  
• Boarding houses (nontransient) with 16 or fewer occupants
  
  
• Boarding houses (transient) with 10 or fewer occupants
  
  
• Care facilities that provide accommodations for five or fewer persons receiving care
  
  
• Congregate living facilities (nontransient) with 16 or fewer occupants
  
  
• Congregate living facilities (transient) with 10 or fewer occupants
  
  
• Lodging houses with five or fewer guest rooms
  

 

[mtlogcabin]

I would prefer to see wall #1 rated because it would afford extra protection for those existing the R-3 if the fire was in the B occupancy

 

[Robert]

Thanks for the replies.....Ron, the building is an existing unsprinklered Type VB building. I am not adding any square footage to the B occupancy and there is no B occupancy on the middle or upper floors. CDA....it is a single family dwelling above (with its entry at the B level) for the R-3. Mtlogcabin...I was thinking the same as the B is a higher hazard, but I also have 2 interior windows in that wall so it will be an expensive upgrade I think.

 

[steveray]

What is the "change" driving this upgrade?

 

[Robert]

Basement dig out to move the existing B occupancy down to street level (6' +/-) which will make it accessible, and enlarging the existing R occupancy where the B used to be.