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340 MIXES GENERALLY
• Constituent materials and mix design: Achieve constant colour and texture for
each finish type.
• Aggregates for facing mixes: Free from particles which may cause 'popouts', or
unsightly marking or staining.
• Total chloride ion content (maximum): Cl 0.40.
• Admixtures containing calcium chloride: Do not use.

350 SEPARATE FACING AND BACKING MIXES
• Thickness of facing mix at any point (minimum): 20 mm.
• Distance of reinforcement from the junction of the two mixes (minimum): 10 mm.
• Joining facing and backing mixes: Bond so that they are effectively monolithic.

360 CASTING AND CURING
• Compaction: Thorough.
• Protection: Prevent premature drying out during curing period.
• Immature components: Prevent distortion from movement, vibration, overloading,
physical shock, rapid cooling and thermal shock.
• Delivery to site: Not until at least 14 days after casting.

370 QUALITY OF FINISHES
• Appearance standard: As established by samples.

LAYING AND JOINTING

430 ADVERSE WEATHER
• General: Do not use frozen materials and do not lay on frozen surfaces.
• Temperature: Do not lay blocks/ dressings:
• - In cement gauged mortars when the air temperature is at or below 3°C and
falling or below 1°C and rising (unless mortar has a temperature of not less than 4°C
when laid and walling is thoroughly protected).
• - In hydraulic lime:sand mortars when the air temperature is at or below 5°C and
falling or below 3°C and rising.
• Freezing conditions: Maintain temperature of the work above freezing until mortar
has fully set.
• Precipitation: Protect newly erected walling against rain and snow by covering
when precipitation occurs and at all times when work is not proceeding.
• Hot and dry conditions: Prevent newly erected masonry from drying out too
rapidly.
• Remedial work: Rake out and replace mortar damaged by frost and where
instructed, rebuild damaged work.

450 WALLING/ DRESSINGS BELOW GROUND LEVEL
• Extent of facework below finished level of adjoining ground or external works level
(minimum): 150 mm.

490 PUTLOG SCAFFOLDING
• Use: Not permitted.

RotF generic (intermediate) NBS 2014 6118-AEW-XX-XX-NBS-A-01