(1) Grade D construction means construction complying with the particular requirements of this section.

(2) Walls and structural frames. – All external walls which have roofs covered with thatch or wooden shingles shall be of non-combustible materials, and except where otherwise provide in subsection (3), all bearing-walls or structural frames shall have a fire-resistance rating of not less than half an hour.

(3) External walls and external members of structural frames. – Non-combustible external bearing-walls and non-bearing-walls and external members of structural frames of a building shall comply with the requirements of subsection (3) of section 9.

(4) Subject to the requirements of subsection (9), the distance between any external wall or structural frame of combustible construction of an occupancy-unit falling under class 11 and another building on the same stand, or between such wall or frame and the nearest lateral boundary of such stand, shall be not less than the distance specified in Table X, in which such walls or frames are placed in the following classes of construction—

Class A. – External walls or external structural frames of combustible construction protected externally with approved non-combustible material; and

Class B. –External walls or external structural frames of combustible construction not falling into class A.

TABLE X
BOUNDARY OR SEPARATION DISTANCES FOR EXTERNAL WALLS OR EXTERNAL MEMBERS OF STRUCTURAL FRAMES OF A BUILDING WHICH ARE COMBUSTIBLE—GRADE D CONSTRUCTION

(5) Floors. – All floors of rooms constructed in the roof-space of any building having a roof covered with thatch or wooden shingles shall be of non-combustible materials having a fire-resistance rating of not less than half an hour.

(6) All floors constructed directly over basements shall have a fire-resistance rating of not less than one hour.

(7) All floors, other than those referred to in subsections (5) and (6), shall have a fire-resistance rating of not less than half an hour:

Provided that no fire-resistance rating shall be required for such floors in the ground storey, if the space beneath such floors is not used for storage purposes.

(8) Roof assemblies. – The roof of every building having external walls of combustible construction shall be covered with non-combustible materials.

(9) Every building having a roof covered with thatch or wooden shingles shall be not less than 10 metres from any boundary whatsoever of the stand upon which such building is to be erected.

(10) All metal used in the attachment of thatch to the roof-members shall be bonded to earth.

(11) All telephone and electricity supply-lines shall be brought by means of underground conduits or cables into every building which has a thatched roof.

(12) Partition-walls. –Every partition-wall in a basement shall be of non-combustible materials. Every doorway in such partition-wall shall be fitted with a fire-door having a fire-resistance rating of not less than half an hour.

(13) Garages. –Every floor separating the remainder of the building from a garage shall be regarded as forming part of an occupancy-separation structure, which shall comply with the requirements of section 43 and shall have no openings whatever therein.

(14) Every wall separating the remainder of the building from garage shall comply with the requirements for an occupancy-separation structure set out in setion43, except that any doorway in such wall shall be fitted with a self-closing door constructed to have a fire-resistance rating of not less than half an hour, and every such doorway shall have a solid stone or concrete threshold raised at least 100 millimetres above the floor of the garage.