SLE Cladding Limited


		Life to first maintenance in the UK.
		Type of environment
Description	*Mass 3/m2 including both sides	External			Internal
Description	*Mass 3/m2 including both sides	Coastal	Industrial & Urban	Suburban & rural	Wet and possibly polluted	Dry and Unpolluted
Type G275	275	S	S	M	XX	VL
Type G350	350	S	S	M	XX	VL
Type G450	450	M	S	L	XX	VL
Type G600	600	L	M	VL	XX	VL
The recommendations for life to first maintenance are based on the premise that the strength and integrity of the sheet would diminish with time after period specified unless maintenance was carried out. S. Short 2 to 5 years: M. Medium 5 to 10 years: L. Long 10 to 20 years. VL. Very Long 20 to 50 years. XX. Further protection with paint is recommended for this type of application . * Minimum average triple spot

External Environments

1/. Costal environment. This type of situation is typically found over the sea shore and may extend several kilometres inland, dependent on the lie of the land and the prevailing wind. Where offshore wind predominates and the land rises steeply the effect is restricted to a very narrow belt of a few hundred metres in width. Attack on zinc coatings can be rapid near the sea particularly if sea spray comes into contact with the zinc.

2/. Industrial and urban environment. The conditions of this type of environment are worst in the areas of intense industrial activity. In moving from the centre of large conurbations into middle urban areas the significance of atmospheric pollution diminishes, and this environment may be said to shade imperceptibly into a rural and suburban environment. Some heavy industrial activities may not be associated with large cities, however, and in these cases the graduation from rural and suburban to and industrial and urban may be very significant over a short distance.

The principal effect is corrosion due to sulphur dioxide attack. Conditions of high humidity and specific chemical pollution (e.g. acid chloride conditions) may increase corrosion dramatically and would require special consideration.

3/. Rural and suburban environment. This environment covers areas away from the coast and remote from industrial and urban activity. Corrosive attack is governed mostly by humidity and rainfall, but is normally less than in either of the other two environments. The effect of local pollution must always be considered.

INTERNAL ENVIRONMENTS

1/. Wet and possibly polluted. This internal environment is subject to high humidity, which may lead to condensation, and to pollution either generated within the building or externally. Examples are swimming baths halls, bleach houses and livestock houses.

2/. Dry (unpolluted). In this type of environment sources of increased humidity or of pollution, arising within the building or externally are absent. This usually implies that the building is uniformly heated and that any condensation will quickly dry out. Examples range from warehouses to centrally heated offices in suburban surroundings and to school classrooms.