Table 6 – Galvanized Coating System – Exposure Class E1
Article Thickness
6 mm
3 mm to < 6 mm
1.5 mm to < 3 mm
< 1.5 mm
Mean coating
thickness m
85 70
55 45
The minimum coating thickness for exterior steelwork where the exposure condition is E2
– as defined above – shall be as in Table 7 below:
Table 7 – Galvanized Coating System – Exposure Class E2
Article Thickness
6 mm
Mean coating
thickness m
85 The minimum coating thickness for exterior steelwork where the exposure condition is E3
– as defined above – shall be as in Table 8 below:
Table 8 – Galvanized Coating System – Exposure Class E3
Article Thickness
6 mm
3 mm to < 6 mm
1.5 mm to < 3 mm
4.1.1.5 Mean coating
thickness m
115 95
70 Fire Protection Coatings
The requirements for fire-protection shall be defined in the Particular Specification.
Coating systems for the provision of fire-protection shall be limited to the systems listed in
Table 9 below.
Table 9 – Fire Protection Coating System
System ID
System 1
System 2
System 3
System 4
System 5
Primer Ethyl silicate Zn-R
Epoxy Zn-R
Ethyl silicate Zn-R or
Epoxy Zn-R
Ethyl silicate Zn-R or
Epoxy Zn-R
Ethyl silicate Zn-R or
Epoxy Zn-R
Fire Protection Coating
1 Thin film intumescent
Intumescent epoxy mastic
2 Lightweight concrete
Fire protection boards/
casings 3
Concrete 4
Notes: 1 Thin intumescent coatings shall only be used in domestic/commercial internal
applications. They shall not be used for external or industrial type projects unless
approved by the Engineer
2 Lightweight concretes shall generally comply with the Concrete Specification and shall
be proprietary mixes based on vermiculite or similar lightweight materials with a
proven fire rating when tested in accordance with BS 476
3 Due to longer-term durability issues, fire-protection systems based on protection
boards or casings shall be applicable for internal applications only
4 Concrete shall comply with the Concrete Specification and shall provide a minimum
cover of 50 mm to the element it is protecting. Where installation is external, the
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