BUILDING CONSTRUCTION.
[Sidenote: Materials.]
[Sidenote: Kunkar Lime.]
_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.
[Sidenote: Stone Lime.]
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.
[Sidenote: Lime Mortar.]
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.
[Sidenote: Soorki.]
_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.
[Sidenote: Sand.]
Sand must be clean, sharp, and free from dirt.
[Sidenote: Khoa.]
_Khoa_ must be broken from thoroughly burnt bricks to pass through a
ring of 1½″ diameter.
[Sidenote: Cement.]
Portland cement must be of the best quality of English manufacture and
comply with the standard tests.
[Sidenote: Cement Plaster.]
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.
[Sidenote: Bricks.]
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.
[Sidenote: Brick-Work.]
Bricks must be laid true to line and level, with joints not exceeding ⅜″
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.
[Sidenote: Pointing.]
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.
[Sidenote: Culverts.]
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.