Khoa.
Khoa must be broken from thoroughly burnt bricks to pass through a ring of 1½″ diameter.
Cement.
Portland cement must be of the best quality of English manufacture and comply with the standard tests.
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.
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.
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.