1985 Ed.]
Building (Construction) Regulations
(CAP. 123
B 57
96. (1) Subject to the provisions of Part XVI (Fire Resisting Construction), where a column or beam is situated wholly or partly in an external wall or wholly or partly within a recess in a party wall, that column or beam shall be solidly encased with brickwork, concrete or other similar material not less than-
(i) 100 mm thick where the encasement of a column is exposed to the weather; and
(ii) 50 mm thick where not so exposed.
(2) Where structural steel may be adversely affected by moisture from the adjoining earth, it shall be solidly encased with concrete not less than 100 mm thick.
(3) For the purpose of this regulation any concrete used in the encasement of steelwork shall be not inferior to that designated Grade III in regulation 19.
97. (1) Subject to the provisions of regulations 97(3), (4) and (5), 99, 101 and 106, the stresses of structural steel (other than columns and struts), shall not exceed the maximum permissible stresses specified in Table XX.
(2) In compound or built-up sections formed with different thicknesses of high yield stress structural steel, the maximum permissible stress for the whole of the section shall be taken as that for the greatest thickness of material used, except that for shear on webs, the maximum permissible stress shall be that specified for the thickness of the web itself.
TABLE XX
Maximum permissible stresses on structural steel (other than columns and struts) in MPa
1
Mild steel complying with the appropriate provisions of BS
High yield stress structural steel complying with the appropriate provisions of BS 4360: 1972
3
Part of structure and kind of stress
For material not exceeding 25 mm in thickness or diameter
For material exceeding 25 mm in thickness or diameter
[Subsidiary]
Protection. L.N. 294/76.
Stresses (steel other than columns and struts). L.N. 294/76.
I.
For parts in tension-
(a) on the net section for axial stress
(b) flexural stress in extreme fibres of slab bases
140
190
170
185
185
185
(c) flexural stress in extreme fibres on the net section of--
(i) beams and girders (other than plate girders)
150
(ii) plate girders.....
145
(d) on shop rivets for axial stress
(e) on field rivets for axial stress
(f) on the net section of bolts for axial stress
210
190
200
185
80
110
100
60
85
80
80
110
100