VB construction non seperated mixed use 2 story building

[skipharper]

Scenerio: Designer proposing a 2 story non seperated mixed use A2/B VB construction. The bottom floor has 6200 sq ft A2 and the top floor (proposed) is 6200 sq ft use group B. I am saying no, the A2 requires sprinklers if it exceeds 5000 sq ft and therefore you cannot also claim the building is sprinkled and so you can add a second floor for the sprinkler increase.

I have suggested calling this a seperated mixed use, break the A@ fire area to below 5000 sq ft and you may then sprinkle the building and gain the story increase.

Thoughts please and as always thanks.

 

[cda]

I am mathematically challenged

Even at 5000 aren't they over 100 occupant load

 

[Builder Bob]

if non-separated, an A-2 cannot be in a two story V-B building.

 

[Mech]

Even at 5000 aren't they over 100 occupant load

Maybe; maybe not. It depends how the floor area is broken up. Kitchens are figured at 1 person per 200 sf. Depending where restrooms are located, exclude them for occupant load purposes.

SkipHarper - Is there a code section that says a sprinkler system used to exceed the 5,000 sf fire area or 100 person occ load cannot also be used simultaneously to increase the max allowable floor area or number of stories?

From the '09 IBC, Section 506.3 Automatic sprinkler system increase, the exceptions listed do not apply to this scenario. I may be missing the section that backs up your position.

If the building were equipped with a second identical sprinkler system, would that allow for both the additional floor and increased fire area size?

 

[skipharper]

The IBC requires sprinklers if you exceed 5000 sq ft in A2 and the occupant load becomes moot because the fire area is 6200 sq ft. I think if the structure were to be seperated into less than 5000 sq ft sections you could then sprinkle and gain the second floor however if the code is requiring sprinklers because you have exceeded 5000 you cannot also then add a story using VB construction.

 

[Francis Vineyard]

Allowed in accordance with section 506.3 and 508.3.2; sprinkler increases the floor area 200% and 1 story. For the building to be Non-sprinklered would require fire areas be kept below maximum allowed with fire barriers in accordance with section 508.4.4.

Francis

 

[RLGA]

Sprinkler system is required--all three conditions apply: 1) the fire area exceeds 5,000 sq. ft., 2) the fire are has an occupant load over 100, and 3) since the second story is not separated from the first, the second floor is part of the A-2 fire area; thus, an A-2 fire area is located on a floor other than the level of exit discharge.

The IBC does not preclude the use of a required sprinkler system for area and height increases. However, the fire sprinkler substitution for 1-hour construction for Types IIA, IIIA, and VA does preclude the use of the sprinkler system for height and area increases.

 

[Francis Vineyard]

In Skips question for the design presented there is a distinction with the sprinkler requirements; one is only for the A-2 fire area that would apply with separated mixed use:

"903.2.1 Group A. An automatic sprinkler system shall be provided throughout buildings and portions thereof used as Group A occupancies as provided in this section. For Group A-1, A-2, A-3 and A-4 occupancies, the automatic sprinkler system shall be provided throughout the floor area where the Group A-1, A-2, A-3 or A-4 occupancy is located, and in all floors from the Group A occupancy to, and including, the nearest level of exit discharge serving the Group A occupancy. For Group A-5 occupancies, the automatic sprinkler system shall be provided in the spaces indicated in Section 903.2.1.5. [F]"

The other is when the whole building is sprinklered in accordance with NFPA 13 for the increase in height and area; this could be acheived with non-separated mixed use.

Francis

 

[steveray]

Great answer Ron....