bulkhead too low?

[Nicole Brooks]

I'm working on an existing building. Current floor to floor is 8'7", I have approximately 7'-7" clear. I have an enclosed bulkhead that has an 8" duct, with approximately 1.5" for connections (so 9.5") and it is enclosed with 2 1/2" studs. So, with drywall that puts me just over 6'-8" clear. the bulkhead is 3.5' wide and cuts across (perpendicular) my exit access corridor. Does a bulkhead fall under exception 1003.3.1: Protruding objects are permitted to extend below the min. ceiling height required by section 1003.2 where a min. headroom of 80" is provided over any circulation path, cooridors, aisles and passageways. Not more than 50% of the ceiling in a means of egress shall be reduced in height by protruding objects.

 

[Yankee Chronicler]

Gotta love regional terminology. Around here, a "bulkhead" is a structure above the roof level of a building, like an elevator penthouse or a rooftop mechanical room.

I don't see anything confusing about IBC section 1003.3 or 1003.3.1.

Your protruding construction provides 80" if headroom -- check.

The protrusion is 3-1/2 feet wide. What's the width of the corridor and what's the length of the corridor? If the horizontal projection of the protruding duct enclosure is not more than 50% of the ceiling area of the corridor, you're in compliance.

 

[Nicole Brooks]

Gotta love regional terminology. Around here, a "bulkhead" is a structure above the roof level of a building, like an elevator penthouse or a rooftop mechanical room.

I don't see anything confusing about IBC section 1003.3 or 1003.3.1.

Your protruding construction provides 80" if headroom -- check.

The protrusion is 3-1/2 feet wide. What's the width of the corridor and what's the length of the corridor? If the horizontal projection of the protruding duct enclosure is not more than 50% of the ceiling area of the corridor, you're in compliance.

The corridor is 36' long and 9' wide

 

[Yankee Chronicler]

Assuming uniform corridor width, the protrusion is 3.5' long and the corridor is 36' long. That's 9.7%, which is considerably less than 50%.

 

[bill1952]

Gotta love regional terminology. Around here, a "bulkhead" is a structure above the roof level of a building, like an elevator penthouse or a rooftop mechanical room.

And outside entrance to the basement - a Bilco door - was a bulkhead where I grew up in upstate NY.

 

[Yankee Chronicler]

And outside entrance to the basement - a Bilco door - was a bulkhead where I grew up in upstate NY.

I have encountered that one, as well. Never before heard of a duct with a sheetrock wrap being called a "bulkhead."

 

[bill1952]

I have heard and maybe used it for a duct below ceiling and against wall - a kind of soffit.

From Merriam Webster

1: an upright partition separating compartments

2: a structure or partition to resist pressure or to shut off water, fire, or gas

3: a retaining wall along a waterfront

4: a projecting framework with a sloping door giving access to a cellar stairway or a shaft

 

[e hilton]

If you’re concerned and want a little cushion on the headroom, convert the 8” round duct to a 3” or 4” h x whatever width rectangle.

 

[Nicole Brooks]

I have heard and maybe used it for a duct below ceiling and against wall - a kind of soffit.

From Merriam Webster

1: an upright partition separating compartments

2: a structure or partition to resist pressure or to shut off water, fire, or gas

3: a retaining wall along a waterfront

4: a projecting framework with a sloping door giving access to a cellar stairway or a shaft

LOL it was new to me too when I moved to the mid-Atlantic, would have referred to it as a soffit before.

 

[TheCommish]

A soft is the build out above the kitchen cabinets, or the space under the roof overhang, or the boxing out of the mechanical at the permitter of the room

 

[Yankee Chronicler]

Definition of SOFFIT

the underside of a part or member of a building (as of an overhang or staircase); especially : the intrados of an arch… See the full definition

www.merriam-webster.com

soffit​

noun​

sof·fit ˈsä-fət

: the underside of a part or member of a building (as of an overhang or staircase)
especially : the intrados of an arch

 

[bill1952]

Definition of SOFFIT

the underside of a part or member of a building (as of an overhang or staircase); especially : the intrados of an arch… See the full definition

www.merriam-webster.com

Does "underside" as used here imply level? I noted "stair" and it never occured the boxed in sloped part under a stair was a bulkhead.

A soft is the build out above the kitchen cabinets

Assuming spell correct are your "soffit", would the build out still be a soffit if there were no cabinets?

 

[TheCommish]

Sssspell check at work, Soffit lacking a cabinets I would still call it a soffit

 

[Yankee Chronicler]

Sssspell check at work, Soffit lacking a cabinets I would still call it a soffit

How about a reception desk in a doctors' office waiting room? We're seeing a lot of medical offices in which the general waiting room has an acoustical tile (lay-in) ceiling at, say, 9 feet AFF, and above the reception desk there's a dropped section of sheetrock ceiling at 8 feet AFF. It's in the middle of the room, not along any wall. We call that a soffit.

 

[tmurray]

We call it a bulkhead when it encloses building services.

 

[TheCommish]

YC, I wouldn't argue that the dropped ceiling could be called a soffit, or could we call it a conferred ceiling

 

[Yankee Chronicler]

YC, I wouldn't argue that the dropped ceiling could be called a soffit, or could we call it a conferred ceiling

I've been at this for more than fifty years, and that's a term I've never encountered before.

 

[bill1952]

YC, I wouldn't argue that the dropped ceiling could be called a soffit, or could we call it a conferred ceiling

coffered ceiling?

 

[TheCommish]

 

[MtnArch]

Toe-may-toes / Tow-mah-toes ...

 

[SCBO1]

Be aware of your MEP plans and any hang-down lighting or exit lighting could become an issue?

I've been at this for more than fifty years, and that's a term I've never encountered before.

How bout Fur-down, have you heard that one?

 

[Yankee Chronicler]

How bout Fur-down, have you heard that one?

Nope. Another regional difference, I guess.