Section 50.11. Construction tables  


Latest version.
  • (a) Fireresistive construction. Fireresistive construction shall be the type of construction in which the walls, floors, roof and structural members are steel, iron, masonry, concrete or other noncombustible materials meeting all of the requirements of this chapter and having a minimum fireresistive rating as indicated in the construction table.

    CONSTRUCTION TABLE


    Component
    Description
    Minimum Fireresistive
    Rating
    WALLS
    Exterior bearing walls… 3-hour Noncombustible
    Exterior panel and curtain walls… 1-hour Noncombustible
    PARTITIONS
    Bearing partitions… 2-hour Noncombustible
    (1 1/2-hour B Label door assemblies)
    Nonbearing partitions… 1-hour Noncombustible
    (3/4-hour C Label door assemblies)
    Partitions enclosing stairs and other vertical openings… 2-hour Noncombustible
    (1 1/2-hour B Label door assemblies)
    Partitions enclosing exit access corridors… 1-hour Noncombustible
    (3/4-hour C Label door assemblies)
    COLUMNS
    Supporting Masonry… 3-hour Noncombustible
    Other… 3-hour Noncombustible
    Supporting roofs only… 2-hour Noncombustible
    GIRDERS AND TRUSSES
    Supporting masonry walls… 3-hour Noncombustible
    Other… 3-hour Noncombustible
    Supporting roofs only… 1-hour Noncombustible
    FLOOR PANELS—Including beams and joists… 2-hour Noncombustible
    ROOF PANELS—Including beams and joists… 1-hour Noncombustible



    EXCEPTIONS TO CONSTRUCTION TABLE


    1. Structural steel and iron members which are used exclusively for elevators and are not part of the structural frame of the building may be unprotected.

    2. Fire protective covering may be omitted from structural steel roof structures and members of concrete roof structures of buildings where every part of the roof structure is 20 feet or more above any floor and 10 feet above any balcony or gallery for A, B and C occupancy groups.

    3. Nonbearing partitions subdividing an area of 10,000 square feet or less and occupied by a single tenancy may be of fire-retardant treated wood or metal panels without a fireresistive rating.

    4. Bays, porches, exterior balconies, and any projections shall be constructed of noncombustible materials.

    5. Penthouses and all other roof structures shall be considered part of the next lower story. Where the exterior wall of a penthouse is recessed five feet or more from the next lower story’s exterior wall and the exterior wall of the next lower story is required to have a fireresistive rating greater than 1 1/2 hours, the penthouse walls may be constructed of noncombustible materials with a minimum rating of 1 1/2 hours.

    6. Panel walls of noncombustible construction attached to the structural frame may be used when no undue hazard is deemed to exist.

    (b) Noncombustible construction. Noncombustible construction shall be the type of construction in which all structural members including walls, floors, roofs and their supports are steel, iron, masonry, concrete, or other noncombustible materials having a minimum fireresistive rating as indicated in the construction table.

    CONSTRUCTION TABLE


    Component
    Description
    Minimum Fireresistive
    Rating
    WALLS
    Exterior bearing walls… Noncombustible
    Exterior panel and curtain walls… Noncombustible
    Penthouse enclosure walls… Noncombustible
    PARTITIONS
    Bearing partitions… Noncombustible
    Nonbearing partitions… Noncombustible
    Partitions enclosing stairs and other vertical openings… 1-hour Noncombustible
    (3/4-hour C Label fire door assemblies)
    Partitions enclosing exit access corridors… 1-hour Noncombustible
    COLUMNS
    Supporting Masonry… Noncombustible
    Other… Noncombustible
    Supporting roofs only… Noncombustible
    GIRDERS AND TRUSSES
    Supporting masonry walls… Noncombustible
    Other… Noncombustible
    Supporting roofs only… Noncombustible
    FLOOR PANELS—Including beams and joists… Noncombustible
    ROOF PANELS—Including beams and joists… Noncombustible



    EXCEPTIONS TO CONSTRUCTION TABLE


    1. Nonbearing partitions subdividing an area and occupied by a single tenancy may be of fire-retardant treated wood or metal panels without a fireresistive rating.

    2. Bays, porches, exterior balconies, and any projections may be constructed of noncombustible materials, or exterior fire-retardant treated wood.

    3. Panel walls of fire-retardant treated wood attached to the structural frame may be used when no undue hazard is deemed to exist.

    4. Roof construction, including beams and joists may be fire-retardant treated wood.

    (c) Protected heavy timber. Protected heavy timber shall be the type of construction in which the exterior walls and fire walls are of masonry, reinforced concrete, or other approved noncombustible materials meeting the requirements of this chapter and having a fireresistive rating as indicated in the construction table. Heavy timber members of the following minimum nominal sizes may be used as an alternative to the construction table without meeting the minimum fireresistive rating.


    Columns 8" x 8"
    Trusses supporting floors6" x 6"
    Trusses supporting roofs only4" x 6"
    Girders supporting floors8" x 10"
    Girders supporting roofs only6" x 10"
    Beams supporting floors6" x 10"
    Beams supporting roofs only4" x 8"
    Floor panels3"
    Roof panels2"

    CONSTRUCTION TABLE


    Component
    Description
    Minimum Fireresistive
    Rating
    WALLS
    Exterior bearing walls… 2-hour Noncombustible
    Exterior panel and curtain walls… 2-hour Noncombustible
    PARTITIONS
    Bearing partitions… 1-hour Noncombustible
    (3/4-hour C Label door assemblies)
    Nonbearing partition… 1-hour Noncombustible
    (3/4-hour C Label door assemblies)
    Partitions enclosing stairs and other vertical openings… 1-hour Noncombustible
    (3/4-hour C Label fire door assemblies)
    Partitions enclosing exit access corridors… 1-hour Noncombustible
    (3/4-hour C Label door assemblies)
    COLUMNS
    Supporting Masonry… 2-hour Noncombustible
    Other… 2-hour Noncombustible
    Supporting roofs only… 1-hour Noncombustible
    GIRDERS AND TRUSSES
    Supporting masonry walls… 1-hour Noncombustible
    Other… 1-hour Noncombustible
    Supporting roofs only… 1-hour Noncombustible
    FLOOR PANELS—Including beams and joists… 1-hour Noncombustible
    ROOF PANELS—Including beams and joists… 1-hour Noncombustible



    EXCEPTIONS TO CONSTRUCTION TABLE


    1. Timber arches or trusses may be used to support roof loads. The framing members shall be of not less than 4 inches by 6 inches nominal dimensions, except that spaced members may be composed of two or more pieces, each of not less than three inch nominal thickness when blocked solidly throughout their intervening spaces or when such spaces are tightly closed by a continuous wood cover plate of not less than 2 inch nominal thickness secured to the underside of the members. Splice scabs shall be not less than 3 inch nominal thickness. When protected by approved automatic sprinklers under the roof deck, the framing members may be reduced to not less than 3 inch nominal thickness.

    2. Floors may be constructed of splined or tongue and groove plank of not less than 3 inch nominal thickness, covered with 1 inch flooring laid crosswise or diagonally or may be of laminated construction consisting of planks of not less than 4 inch nominal width, laid on edge and spiked together at intervals of 18 inches and covered with 1 inch flooring. Laminated floors shall be laid with staggered joints and shall not be spiked to the supporting girders.

    3. Structural steel and iron members which are used exclusively for elevators and are not part of the structural frame of the building may be unprotected.

    4. Fire protective covering may be omitted from structural steel roof structures and members of concrete roof structures of buildings where every part of the roof structure is 20 feet or more above any floor and 10 feet above any balcony or gallery for A, B and C occupancy groups.

    5. Nonbearing partitions subdividing an area of 10,000 square feet or less and occupied by a single tenancy may be of fire-retardant treated wood or metal panels without a fireresistive rating.

    6. Bays, porches, exterior balconies, and any projections shall be constructed of noncombustible materials.

    7. Penthouses and all other roof structures shall be considered part of the next lower story. Where the exterior wall of a penthouse is recessed five feet or more from the next lower story’s exterior wall and the exterior wall of the next lower story is required to have a fireresistive rating greater than 1 1/2 hours, the penthouse walls may be constructed of noncombustible materials with a minimum rating of 1 1/2 hours.

    8. Panel walls of noncombustible construction attached to the structural frame may be used when no undue hazard is deemed to exist.

    (d) Ordinary construction. Ordinary construction shall be the type of construction in which the exterior walls are of masonry, concrete or other noncombustible material meeting the requirements of this chapter and having a minimum fireresistive rating as indicated in the construction table. Interior framing may be partially or wholly of wood.

    CONSTRUCTION TABLE


    Component
    Description
    Minimum Fireresistive
    Rating
    WALLS
    Exterior bearing walls… 2-hour Noncombustible
    Exterior panel and curtain walls… Noncombustible
    Penthouse enclosure walls… 2-hour Noncombustible
    PARTITIONS
    Bearing partitions… None
    Nonbearing partitions… None
    Partitions enclosing stairs and other vertical openings… 1-hour
    (3/4-hour C Label fire door assemblies)
    Partitions enclosing exit access corridors… 1-hour
    (3/4-hour C Label fire door assemblies)
    COLUMNS
    Supporting masonry… None
    Other… None
    Supporting roofs only… None
    GIRDERS AND TRUSSES
    Supporting masonry walls… None
    Other… None
    Supporting roofs only… None
    FLOOR PANELS—Including beams and joists… None
    ROOF PANELS—Including beams and joists… None



    EXCEPTIONS TO CONSTRUCTION TABLE


    1. Structural steel and iron members which are used exclusively for elevators and are not part of the structural frame of the building may be unprotected.

    2. Firestopping shall be provided in all walls at each floor level to prevent the spread of fire. Horizontal concealed spaces shall be provided with draftstopping each 3,000 square feet. Draftstopping and firestopping materials shall be not less than 1/2 inch gypsum board, 3/8 inch plywood or other equivalent material.

    3. No wood framing shall be placed within two inches of the outside of chimneys. This distance may be reduced to 1/2 inch if the members are faced to their full depth with approved insulating material not less than 1/4 inch thick. No wood framing shall be placed within four inches of the backwall of any fireplace. Header beams supporting trimmer arches of fire places shall be not less than 20 inches from the face of the chimney breast.

    4. All wood shingles shall be pressure treated to meet the requirements for Class C roof covering in accordance with the Standard Test ASTM E-180 ‘‘Test for Roof Covering’’ including the weathering test.

    5. Solid core wood doors equal to or greater than a 20 minute fireresistive rating may be used for corridor partitions. These doors shall be self-closing and have positive latching.

    (e) Wood frame construction. Wood frame construction shall be the type of construction in which structural members and their support are constructed of wood or are dependent upon wood for support and having a minimum fireresistive rating as indicated in the construction table.

    CONSTRUCTION TABLE


    Component
    Description
    Minimum Fireresistive
    Rating
    WALLS
    Exterior bearing walls… None
    Exterior panel and curtain walls… None
    Penthouse enclosure walls… None
    PARTITIONS
    Bearing partitions… None
    Nonbearing partitions… None
    Partitions enclosing stairs and other vertical openings… 1-hour
    (3/4-hour C Label fire door assemblies)
    Partitions enclosing exit access corridors… 1-hour
    COLUMNS
    Supporting Masonry… None
    Supporting roofs only… None
    General support… None
    GIRDERS AND TRUSSES
    Supporting masonry walls… None
    Other… None
    Supporting roofs only… None
    FLOOR PANELS—Including beams and joists… None
    ROOF PANELS—Including beams and joists… None



    CONSTRUCTION TABLE NOTES


    1. Firestopping shall be provided in all walls at each floor level to prevent the spread of fire. Horizontal concealed spaces shall be provided with draftstopping each 3,000 square feet. Draftstopping and firestopping materials shall be not less than 1/2 inch gypsum board, 3/8 inch of plywood or other equivalent material.

    2. All wood shingles shall be pressure treated to meet the requirements for Class C roof covering in accordance with the Standard Test ASTM E-180 ‘‘Test for Roof Covering’’ including the weathering test.

    3. Solid core wood doors equal to or greater than 20 minute fireresistive rating may be used for corridor partitions. These doors shall be self-closing and have positive latching.

Notation

Cross References

This section cited in 34 Pa. Code § 49.1 (relating to definitions); 34 Pa. Code § 50.25 (relating to stair towers); and 34 Pa. Code § 50.43 (relating to classification).