Kunkar lime should be burnt near the site of works from clean kunkar with coal or charcoal. When the burnt kunkar is taken out of the kiln it must not be slaked, but after any clinker has been removed, should be ground fine enough to pass through a screen of 400 meshes to the square inch, and must be used freshly ground. It should contain over 40 per cent. of Oxide of Calcium.

Stone lime should be obtained unslaked. Before being used it must be slaked and sifted through a screen of 400 meshes to the square inch.

Lime mortar to consist of fresh lime mixed by measure with sand or soorki in one of the following proportions, as may be directed:—

(a)

1 Kunkar lime.

2 Soorki.

(b)

1 Kunkar lime.

1 Soorki.

1 Sand.

(c)

1 Kunkar lime.

2 Sand.

(d)

1 Stone lime.

2 Soorki.

2 Sand.

(e)

1 Stone lime.

3 Soorki.

1 Sand.

(f)

1 Stone lime.

4 Soorki.

(g)

should not be used in the dry season as it sets too quickly.

The materials should be spread in layers not exceeding 3 inches in thickness, and then incorporated in a steam mortar mill, or bylechuki, with sufficient water to make it into a stiff paste. Mortar which has once commenced to set should on no account be used in any work.

Kunkar or Hydraulic lime must invariably be used for waterworks and for wet foundations.

Soorki must be made from well burnt brick-bats, and must pass through a sieve of 1
16 × 1
16 mesh. Freshly burnt bats must only be used.

Sand must be clean, sharp, and free from dirt.

Khoa must be broken from thoroughly burnt bricks to pass through a ring of 1½ diameter.

Portland cement must be of the best quality of English manufacture and comply with the standard tests.

Cement plaster to be made of one part of Portland cement to two parts of sand, and must be properly mixed and applied fresh, the thickness of each layer to be ½ finished. The surface must be kept covered with wet bags or straw for at least three days, after it has been completed.

Bricks must be hard, well burnt, sound, true to shape and size, and free from flaws and other imperfections, and to be of approved sample.

Bricks must be laid true to line and level, with joints not exceeding ? in thickness, and of approved bond. They must be soaked in water for at least four hours before being used. All joints must be raked out to a depth of ½, while the mortar is fresh.

All joints to be at least ½ in depth, and thoroughly cleaned out by watering and rubbing with a brush. Mortar for pointing to be composed of one part of lime and one part of soorki, ground very fine in a mill, or strained through coarse cloth. Flush pointing to be lined off true horizontally and vertically with a string, the lines thus made to be deepened by a rule made for the purpose.

The type of culverts adopted must be dependent on the depth of the drain below the surface of the road. Where arching can be done it is preferable. Where impracticable, the top should be covered with stone slabs. Parapets should be provided with stone copings. All culverts on a road or street should be numbered, and registered in the form given in Appendix G, page 74.

The system of quadrennial repairs to bridges and culverts is an essential towards efficient administration, and when once successfully introduced, is economical.

In masonry buildings a damp-proof course, which may be made with either asphalte, or with a layer of Portland cement 1 in thickness, laid at the top of the plinth, and just above floor-level, is most desirable in order to prevent damp rising in the walls, if for no other reason than that it prevents damage to the masonry, and to the plastering, or pointing.