Detailed specification of brick work in 1:6 mortar

Detailed specification: brick work in cement sand mortar 1:6

Scope: Providing and constructing brick masonry in cement sand mortar 1:6 (1 cement : 6 sand by volume) for walls above plinth, including scaffolding, curing and cleaning, as per drawings and the engineer's instructions.

Materials

• Bricks: first-class, well burnt, regular in shape (240 × 115 × 57 mm), uniform in colour, giving a ringing sound when struck; compressive strength as specified (first-class bricks normally not less than about 10 N/mm², and never below the NBC minimum of 3.5 N/mm²); water absorption not more than 20%; no cracks or lime lumps. Soaked in water for at least 2 hours before laying.
• Cement: OPC 43 or PPC, fresh, free of lumps, kept in a dry store.
• Sand: clean, coarse river or pit sand, free from clay, silt (< 4%), organic matter and salt; FM 1.5–2.5.
• Water: clean and potable.

Mortar: cement and sand 1:6 by volume (gauge boxes), dry-mixed until uniform in colour, then mixed with just enough water. Mortar must be used within 30 minutes of mixing; it must not be re-tempered.

Workmanship

• Brickwork in the bond shown (English or Flemish); full bed of mortar, all joints filled.
• Joint thickness 10 mm (max. 12 mm); face joints raked 12–15 mm deep for plastering.
• Courses level and plumb, checked by line, plumb bob and spirit level; vertical joints staggered.
• Raising limited to 1 m per day; where work stops, it is raked back (stepped) according to the bond, with toothing only where future extension is planned.
• Openings left, and lintels and sleeves placed, as per drawing; bearings for slabs/beams finished flat.

Curing: keep wet for at least 7 days; protect fresh work from rain and sun.

Tolerance: plumb within 5 mm per 3 m height.

Measurement and payment: measured in cubic metres of finished work; openings over 0.1 m² deducted. The rate includes all materials, labour, scaffolding, curing and wastage.