B 124
CAP. 123 Building (Construction) Regulations
[1985 Ed.
{Subsidiary]
L.N. 294/76.
THIRD SCHEDULE
[reg. 182.]
MINIMUM REQUIREMENTS FOR CONSTRUCTION AND MATERIALS TO BE CAPABLE OF RESISTING THE ACTION OF FIRE FOR SPECIFIED PERIODS
TABLE A
WALLS AND PARTITIONS
Minimum thickness in mm (excluding plaster) for period of
Construction and Materials
3 hours 4 hours 1 hour 4 hours 2 hours 1 hour
SOLID CONSTRUCTION--
Bricks of clay, concrete or sand lime
No plaster
*Where plastered at least 12.5 mm thick on each side and where the wall does not exceed 3 m in either height or length, the thickness for this period may be 100 mm.
225 225* 100 100
Concrete blocks
Class 1 Aggregate
No plaster.
100
Plastered at least 12.5 mm thick on each side
100
Class 2 Aggregate
No plaster
100
Plastered at least 12.5 mm thick on each side
100
Gypsum blocks
No plaster
100
Plastered at least 12.5 mm thick on each side
75 75 65 50 75 75 75 50
Wood wool slabs Plastered at least 12.5 mm thick on each side
75 50 50
Reinforced concrete
Plaster board
HOLLOW BLOCK CONSTRUCTIONS- Clay blocks
Aggregate in accordance with regulation 18(2), with minimum concrete cover to reinforcement of 25 mm
Supported at top and bottom edges in steel channels and plastered on each side at least 15 mm thickness with gypsum plaster
Plastered at least 12.5 mm thick on each side and shells not less than 20 mm thick:-
175 100 75 75
1 cell in each block and each block not less than 50 per cent solid
100 75
1 cell in each block and each block not less than 30 per cent solid
150
2 cells in each block and each block not less than 50 per cent solid
225 100
2 cells in each block and each block not less than 30 per cent solid
150