Table 11.

The items and standards for formwork operation

Activity	Item	Standard
Formwork operation	(a) Formwork dimensions and openings for services	1. Tolerance for cross-sectional dimensions of cast in situ and precast elements: + 10 mm/ − 5 mm
		2. Tolerance for penetration/opening for services: + 10 mm for size and ± 25 mm for location
		3. Tolerance for length of precast members:   • Lower than 3 m: ± 6 mm   • Between 3 m and 4.5 m: ± 9 mm   • Between 4.5 m and 6 m: ± 12 mm   • Higher than 6 m: ± 6 mm
	(b) Alignment, plumb, and level	1. Tolerance for the departure of any point from its position: 10 mm
		2. Tolerance for plumb: 3 mm/m, max 20 mm
		3. Maximum deviation of the mean level of staircase thread to temporary benchmark: ± 5 mm
		4. For cast-in situ elements, the deviation of level of any point from the intended level: ± 10 mm
	(c) Condition of formwork, props, and bracing	1. Formwork should be free from faults
		2. Before concreting, the interior should be free from residue
		3. All formwork joints should not have gaps to hamper leaking
		4. There should be adequate support, bracing, and tie-back for the formwork to prevent bulging or displacement of structural elements