IS: 1200 (Part V) – 1982 ; method of measurement of formwork
- SCOPE
1.1 This standard (Part V) covers the method of measurement of formwork separately. - GENERAL RULES
2.1 Items may be clubbed together provided they are based on detailed descriptions as stated in this standard.
2.2 In booking dimensions, the order shall be consistent and generally in the sequence of length, breadth or width, and height or depth or thickness.
2.3 The description of each item shall include, where necessary:- Conveyance, delivery, handling, loading, unloading, storing,
- Fabrication,
- Hoisting, lowering,
- All labor for finishing to required shape and size, and levels of striking and removal.
2.4 All work shall be measured net in the decimal system, as fixed in its place: - Dimensions shall be measured to the nearest 0.01 m.
- Areas shall be worked out to the nearest 0.01 m².
2.5 Work to be measured separately: - Work in or under water,
- Work in liquid mud,
- Work in or under foul positions,
- Work interrupted by tides.
- The levels of high and low water tides, where occurring, shall be stated.
- Where springs requiring pumping are likely to be encountered, the work shall be measured against a separate specific provision made for the purpose (see 2.5.3).
- Special pumping, where resorted to, shall be measured separately for all stages of pumping, including intermediate stages, unless stated otherwise, in kilowatt hours or HP hours, against specific provision made for the purpose.
2.6 The bills of quantities shall fully describe the materials and workmanship and accurately represent the work to be executed.
2.7 Measurement in stages: - Work shall be measured under stages stating the height or depth:
- Below ground/datum level,
- Above ground/datum level.
- The ground datum level shall be specified in each case.
- DESCRIPTION OF FORMWORK
3.1 The formwork shall include the following:- Splayed edges,
- Notchings,
- Allowance for overlaps and passings at bolting, nailing, wedging,
- Sheathing battens,
- Strutting,
- Easing,
- Striking and removal,
- All supports, struts, braces, wedges, mud sills, piles or other suitable arrangements to support the formwork,
- Bolts, wire ties, clamps, spreaders, nails, or any other items to hold the sheathing together,
- Scaffolds, ladder, gangways, and similar items,
- Filleting to form stop-chamfered edges or splayed external angles not exceeding 20 mm wide to beams, columns, and the like,
- Temporary openings in the forms for pouring concrete, inserting vibrators, and cleaning holes for removing rubbish from the interior of the sheathing before pouring concrete,
- Dressing with oil to prevent adhesion,
- Raking or circular cutting.
- TYPE OF FORMWORK
4.1 Separate items shall be provided for formwork surface, such as:- Timber formwork (that is, sheathing formed from sawn timber),
- Sheathing formed from tongued and grooved boards,
- Sheathing having plywood lining,
- Sheathing having special lining or any other arrangement to give extra smooth finish or texture or decorative surface for architectural concrete,
- Sheathing of steel sheeting, tubing, or other varieties,
- Slip form technique extrusion process.
- CLASSIFICATION
5.1 Formwork shall be generally classified separately, unless specified otherwise, as follows and measured:- Foundation, footings, bases of columns, etc., and mass concrete,
- Flat surfaces, such as soffits of floors, roofs landing and the like; where floors exceed 200 mm in thickness, the formwork shall be measured separately stating the thickness,
- Vertical surfaces, such as walls, partitions, and the like, including attached pilasters, buttresses, plinth and string courses, etc.,
- Sloping or battering surfaces, including folded plates,
- Arches:
- Up to 6 m span,
- Above 6 m span,
- Cylindrical shells (area of underside to be measured),
- Radius less than 3 m,
- Radius above 3 m,
- Wafer or ribbed slabs where shuttering is required for bottom inclined surface,
- Dormer vaults and shell roofs having curved surfaces in both directions (only the area of underside shall be measured),
- Sides and soffits of beams, beam haunchings, cantilevers, girders, bressumers, and lintels; beams and girders 1 m deep and over shall be measured separately,
- Sides of columns, piers, pillars, posts, and stanchions and struts (square/rectangular/polygonal/circular/curved to be measured separately),
- Edges of slabs and breaks in floors and walls (to be measured in running metres where under 203 mm width or thickness),
- Cornices and mouldings,
- Small surfaces, such as cantilever ends, brackets, and ends of steps, caps and bases to pilasters and columns, etc.,
- Chullah hoods, edges, weather shades, Chhajjas, corbels, etc., including risers and staircases with sloping or stepped stringers, excluding landing,
- Spiral staircases,
- Chimneys and shafts,
- Elevated water reservoirs,
- Fins.
- METHOD OF MEASUREMENT
6.1 Formwork shall be measured in square metres as the actual surfaces in contact with the concrete or any other material requiring formwork. Formwork to small features, such as in 5.1 (p), shall be enumerated. Formwork left in shall be so described.
6.2 Where formwork is required to be lined with wallboard, hardboard, polyethylene sheet, or paper lining or to be coated with mould liquid or limewhite, such formwork shall be so described and measured separately.
6.3 Where lining of wallboard, asbestos, cork slab, and the like is of a permanent character and is to be left in, such lining shall be measured separately; the description shall include any necessary fixing to the concrete.
6.4 No deductions shall be made for openings up to 0.4 m². No deduction shall be made for any opening/cutouts when slip form technique is used.
6.5 Raking or circular cutting and rounded or moulded edges shall be measured in running metres. Moulded stoppings shall be enumerated.
6.6 Formwork to secondary beams shall be measured up to the sides of main beams, but no deduction shall be made from the formwork of the main beam where the secondary beam intersects it. Formwork to beam shall be measured up to sides of column, but no deduction shall be made from the formwork to stanchion or column casings at intersections of beam.
