BUILDING CONSTRUCTION 121 



for all good work. They should be dipped in water before being 

 built, in order to remove dust and prevent the brick from immedi- 

 ately absorbing the water from the mortar. In building brickwork, 

 place the most thoroughly burned bricks to the exposed surfaces. 

 Dry bricks when soaked in water should not absorb more than 

 one-sixth to one-eighth of their weight. This is a fair test for 

 bricks which are to be built in positions exposed to the weather. 

 The weight of a brick varies from 5 to 7 Ibs., according to its 

 density. The average weight of a cubic foot of brickwork is one 

 hundredweight. 



Ordinary Building Bricks. Ordinary building bricks vary 

 slightly in size according to the brickwork or district in which 

 they are made, but the Royal Institute of British Architects has 

 agreed upon a standard size for bricks with the Brickmakers' 

 Association. Without going into the details of the specification, 

 it will be sufficient to state that the maximum size of a brick should 

 be 9 inches by 4f inches by 2 n / 16 inches thick, and the minimum 

 size 8$ inches by 4 5 /ie inches by 2| inches thick. Such bricks, when 

 built with s / 16 -inch beds and ^-inch joints, will measure 1 foot in 

 height over four courses and four beds, and will ensure correct 

 bonding in all thicknesses of walling. 



Bricks are hand-made or machine-made, but in any case are 

 moulded. Hand-made bricks are usually wire-cut, and have no 

 frog or depression, which results in a heavier brick and does not 

 bond so well owing to the absence of the frog. Machine-moulded 

 bricks are usually more regular, have a frog on one or both beds, 

 and usually bear the name of the brickwork at which they are made. 

 There is such a variety of ordinary or common bricks that it is 

 impossible to give a list of them. The reader should obtain samples 

 of those procurable in his own district. The ordinary building 

 bricks known as " composition " bricks are not made from a natural 

 brick-making clay, but have the necessary ingredients brought 

 together from various sources. 



Ordinary clay and composition bricks are obtainable in various 

 shapes for special purposes. Bullnose bricks are used for forming 

 rounded corners at doors, windows, piers, corbels, window sills 

 and other projecting parts which, if built with a sharp arris, might 

 injure animals. Splayed bricks are used for intakes, sills, window 

 openings and corbelling. Ordinary bricks, cut to a suitable size 

 and used as closers for scuntions, are known as bats. 



Facing bricks are special bricks made in a variety of kinds for 

 building with ordinary brickwork to give to walls a finish, durable, 

 sanitary or decorative as the case may be. The cheapest and best 



