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Ceiling Height exceptions

J

Jorge

Registered User
Joined
Sep 14, 2016
Messages
12
Location
Miami, FL
I am working with the Florida Building Code, 2014 edition (copied below):

The ceiling height for non-basement habitable space seems to be required to be 7' min. in most cases.
I see an exception for basement beam and ducts where they can be as low as 6'4". I don't see a similar exception for beams and ducts in non-basement situations.

There is an exception in the BUILDING code where they can be 6" lower than the required ceiling height, but in that code, the ceiling height is required to be 7'6". I know of (but can't find the code reference) that beams are allowed to be as low as 6'8", similar to doors.

Does anyone know how low ducts and beams can be in habitable spaces in non-basements?

Thank you.


SECTION R305
CEILING HEIGHT

R305.1 Minimum height.
Habitable space, hallways, bathrooms, toilet rooms, laundry rooms and portions of basements containing these spaces shall have a ceiling height of not less than 7 feet (2134 mm).

Exceptions:

1. For rooms with sloped ceilings, at least 50 percent of the required floor area of the room must have a ceiling height of at least 7 feet (2134 mm) and no portion of the required floor area may have a ceiling height of less than 5 feet (1524 mm).

2. Bathrooms shall have a minimum ceiling height of 6 feet 8 inches (2032 mm) at the center of the front clearance area for fixtures as shown in Figure R307.1. The ceiling height above fixtures shall be such that the fixture is capable of being used for its intended purpose. A shower or tub equipped with a showerhead shall have a minimum ceiling height of 6 feet 8 inches (2032 mm) above a minimum area 30 inches (762 mm) by 30 inches (762 mm) at the showerhead.

R305.1.1 Basements.
Portions of basements that do not contain habitable space, hallways, bathrooms, toilet rooms and laundry rooms shall have a ceiling height of not less than 6 feet 8 inches (2032 mm).

Exception: Beams, girders, ducts or other obstructions may project to within 6 feet 4 inches (1931 mm) of the finished floor.​
 
How about for other than soffits, doors (or casement) openings between rooms or spaces?


R311.2 Egress door. At least one egress door shall be provided for each dwelling unit. The egress door shall be side-hinged,
and shall provide a minimum clear width of 32 inches when measured between the face of the door and the stop, with the door open 90 degrees. The minimum clear height of the door opening shall not be less than 78 inches in height measured from the top of the threshold to the bottom of the stop. Other doors shall not be required to comply with these minimum dimensions. Egress doors shall be readily openable from inside the dwelling without the use of a key or special knowledge or effort.
 
Jorge: I do not have the Florida code you are referencing. It appears to be some form of I-code just from the sections referenced. What is this room to be used for? Location in the building? The section on showers or basement do not apply and if it is not a sloped ceiling in an attic or third floor. I would say the 7' 6" is the minimum.
 
There used to be an exception (for plank and beam type construction) that permitted "Beams and girders spaced not less than 4 feet on center may project not more than 6 inches below the required ceiling height." Where the provisions of the existing building code may be applicable: "An existing building or portion thereof shall not be altered such that the building becomes less safe
than its existing condition."
 
The space is a living room, single family home. There is an existing beam already at 80" AFF, and we wanted to create a mechanical soffit along side, to be finished flush with the beam. Thus, making the apparent beam 32" wide vs the current 9" wide.
Yes, the florida building code is an altered version of the IBC.
 
RJJ, you are right, in this case it would be the IRC.

I wonder why they are not explicit about exceptions for beams and soffits, like they are for such in basements.
 
The code does not really address this issue. The code assumes a minimum of 7'. Studs come as pre-cuts which would give you an 8'1" rough. It sounds like this home is an existing non conforming building, I don't know how old it is or under what code it was built.
 
I allow this even though the soffit is not technically a slope ceiling, but could be done to satisfy the AHJ.
Apparently Florida also permits the Existing Building Code for (IRC) residential.

2017 Florida Building Code - Residential,
R101.2Scope.
The provisions of the Florida Building Code, Residential shall apply to the construction, alteration, movement, enlargement, replacement, repair, equipment, use and occupancy, location, removal and demolition of detached one- and two-family dwellings and townhouses not more than three stories above grade plane in height with a separate means of egress and their accessory structures not more than three stories above grade plane in height.

Exceptions:

  1. 1.Live/work units located in townhouses and complying with the requirements of Section 419 of the Florida Building Code, Building shall be permitted to be constructed in accordance with the Florida Building Code, Residential. Fire suppression required by Section 419.5 of the Florida Building Code, Building where constructed under the Florida Building Code, Residential shall conform to Section P2904
  2. 2.Owner-occupied lodging houses with five or fewer guestrooms shall be permitted to be constructed in accordance with the Florida Building Code, Residential where equipped with a fire sprinkler system in accordance with Section P2904.
  3. 3.Existing buildings undergoing repair, alteration, additions or change of occupancy shall comply with the Florida Building Code, Existing Building.
R101.2.1
The provisions of Chapter 1, Florida Building Code, Building, shall govern the administration and enforcement of the Florida Building Code, Residential.

As for the existing condition is permitted to continue without alterations.

2017 Florida Building Code - Existing
701.2Conformance.
An existing building or portion thereof shall not be altered such that the building becomes less safe or energy efficient than its existing condition.

Exception: Where the current level of safety or sanitation is proposed to be reduced, the portion altered shall conform to the requirements of the Florida Building Code, Building.

Question: Would the addition of a soffit with a slope ceiling be less safe than its existing condition?
As for sloped ceiling the code is silent to its location, in other words it can be any floor or level.

2017 Florida Building Code - Residential,
SECTIONR305
CEILING HEIGHT

R305.1Minimum height.
Habitable space, hallways and portions of basements containing these spaces shall have a ceiling height of not less than 7 feet (2134 mm). Bathrooms, toilet rooms and laundry rooms shall have a ceiling height of not less than 6 feet 8 inches (2032 mm).

Exceptions:
  1. 1.For rooms with sloped ceilings, the required floor area of the room shall have a ceiling height of not less than 5 feet (1524 mm) and not less than 50 percent of the required floor area shall have a ceiling height of not less than 7 feet (2134 mm).
  2. 2.The ceiling height above bathroom and toilet room fixtures shall be such that the fixture is capable of being used for its intended purpose. A shower or tub equipped with a showerhead shall have a ceiling height of not less than 6 feet 8 inches (2032 mm) above an area of not less than 30 inches (762 mm) by 30 inches (762 mm) at the showerhead.
  3. 3.Beams, girders, ducts or other obstructions in basements containing habitable space shall be permitted to project to within 6 feet 4 inches (1931 mm) of the finished floor.
R305.1.1Basements.
Portions of basements that do not contain habitable space or hallways shall have a ceiling height of not less than 6 feet 8 inches (2032 mm).

Exception: At beams, girders, ducts or other obstructions, the ceiling height shall be not less than 6 feet 4 inches (1931 mm) from the finished floor.

As long the ceiling is above 5 ft. the habitable floor area is not reduced.

R304.1Minimum area.
Habitable rooms shall have a floor area of not less than 70 square feet (6.5 m2).

Exception: Kitchens.

R304.2Minimum dimensions.
Habitable rooms shall be not less than 7 feet (2134 mm) in any horizontal dimension.

Exception: Kitchens.

R304.3Height effect on room area.
Portions of a room with a sloping ceiling measuring less than 5 feet (1524 mm) or a furred ceiling measuring less than 7 feet (2134 mm) from the finished floor to the finished ceiling shall not be considered as contributing to the minimum required habitable area for that room.
 
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Frances: I think this become a judgement call. First the existing ceiling is under 7'. With a dropped beam. To run a duct along side to an existing condition, as long as it is not a worst setup I would say is ok. However, the final call is up to the local AHJ or the appeals board.
 
can you say that the minimum room area - 70 sq. ft. and at least 7' wide in one direction will maintain the required ceiling height, and the area of the soffit/duct falls beyond the minimum room area so its ok? - if all that was true?
 
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