Estimation And Quantity Surveying

Estimation And Quantity SurveyingCONTENTSDADOBrief Specification Detailed Specification Rate Analysis

FLY OVER Approximate Estimate

Brief Specification for DadoProvide dado on 12 mm thick rough cement plaster (1:3) base and jointed with alkali resisted cement as per IS: 4457 completed as per the direction of Engineer-In-Charge.

Detailed Specification for DadoMaterialsPreparation of surface & layingMortar and beddingFixing tiles for dadoCleaning Pointing and finishing Mode of measurement

MATERIALS

White Glazed Tiles : The tiles shall be of approved and shall generally conform to IS : 777. They shall be flat and true to shape and free from cracks, blisters, welts, crawling, crazing spots, chipped edges, corners or other imperfections detracting from their appearance.The tiles shall be of square or rectangular of nominal sizes such as 300x200mm, 150x150mm, 100x100mm.Samples of tiles shall be got approved by the Engineer-in-charge before use on the work. Top surface of tile shall be glossy or matt as specified.

PREPARATION OF SURFACE & LAYINGSub grade concrete or RCC slab or side brick wall/ or plastered surfaces on which tiles are to be laid shall be cleaned, wetted and mopped.The bedding/backing for the tile shall be of C.M. 1.3 or as specified and shall be applied and allowed to harden. The mortar shall be roughened with wire brushes or by scratching diagonal lines 1.5mm. deep at 7.5mm.dado shall be truly horizontal and joints truly vertical. After the tiles have been laid, surplus cement grout shall be cleaned off.

MORTAR AND BEDDING

Cement mortar shall conform to the specification for materials, preparations etc. as specified under cement mortar. The amount of water added while preparing mortar shall be the minimum necessary to give sufficient plasticity for laying.Care shall be taken in preparation of the mortar to ensure that there are no hard lumps that would interfere with even bedding of the tiles.The mortar of specified proportion and thickness shall then be even and smoothly spread over the base by use of screed battens to proper level or slope.

FIXING TILES FOR DADO

The dado work, shall be done only after fixing the tiles/slabs on the floor.The approved white glazed tiles before laying shall be soaked in water for at least 2 hours.Tiles shall be fixed when the cushioning mortar is still plastic and before it gets very stiff. The back of the tile shall be covered with this layer of cement mortar 1:2 using fine sand (table III, zone IV, I.S. 383-1963) and the edge of the tile smeared with neat white cement slurry.The tile shall then be pressed in the mortar and gently tapped against the wall with a wooden mallet.

The fixing shall be done from bottom of wall upwards without any hollows in the bed of joints. Each tile shall be as close as possible to one adjoining. The tiles shall be jointed with white cement slurry. Any thickness difference in the thickness of the tiles shall be arranged out in cushioning mortar so that all tiles faces are in one vertical plane.The top of the dado shall be touched up neatly with the rest of the plaster above. After fixing the dado/skirting etc. they shall be kept continuously wet for 7 days. If doors, windows or other openings are located within the dado area, the corners, sills, jambs etc. shall be provided with true right angles without any specials.

CLEANINGAfter the tiles have been laid in a room or the days fixing work is completed, the surplus cement grout that may have come out of the joints shall be cleaned off before it sets.After the complete curing, the dado or skirting over shall be washed thoroughly clean.In the case of flooring, once the floor has set, the floor shall be carefully washed clean and dried.When dry, the floor shall be covered with oil free dry saw dust.It shall be removed only after completion of the construction work and just before the floor is used.