- Lime terracing on roof shall be composed of brick aggregate of 25 mm. (nominal) size unless otherwise specified, surki and Bisra or Satna lime in the specified proportion.
- Lime concrete shall be laid (and not thrown) in a single layer and spread and rammed,with wooden rammers of weight not exceeding 2 kg. to the specified average thickness, slopes and levels. The concrete shall be used when it is quite fresh. Concrete left over from the previous day’s work shall in no circumstances be used. During this preliminary ramming the surface shall be tested and kept perfectly true to slope, line and level and even by means of a trowel, straight edge and spirit level. The concrete shall then be further consolidated by two rows of labourers sitting close and beating the concrete in union with wooden thappies (weight 1 to 2 kg.) across the entire width of the roof and thus slowly traversing the length of the roof. Special care shall be taken to consolidate the concrete properly at its junction with the parapet wall. This beating shall be continued for three to four days or more until the mortar is almost set and the wooden thappies rebound from the surface readily when struck on it, causing a ringing sound to emit.
- During the operation of mixing, “Kunji” water is to be sprinkled and allowed to soak well in. Lime water must be continuously sprinkled on the terracing to keep it wet whilst being beaten. The mortar which comes to the surface of the terracing during the beating shall be rendered smooth and finished off with lime rubbing and afterwards with oil. Concrete shall be kept wet after each day’s work by spreading straw, and watering very frequently, so as to ensure thorough setting of the concrete.Mouths of rain water pipes shall be properly finished as per direction. The slope of the finished terrace shall not be less than 1in 48. unless a flater slope is desired by the Engineer-in-Charge. The roof surface shall slope from all sides towards the outlets. The minimum thickness of concrete at junction with parapet shall be 75 mm. and shall be rounded. The concrete should be leak-proof and free from cracks.