there are three major categories of brick usage whether it is a pressed bricks
or a wire-cut brick types. Use of both types fall under three categories as
follows: * The facing brickwork is meant for visible decorative work.
- Engineering brick work, using engineering bricks often seen in
bridges and a large industrial construction but may also be hidden in ground
works where maximum durability is required. E.g. in man hole construction.
- Common brickwork is not usually seen and is used where engineering
qualities are not required; below ground in domestic buildings and internal
walls, for instance.
Frog up/down: a frog is recessed part of a surface work of a brick. Pressed
bricks are laid �frog up� when maximum strength is required especially in
engineering work. This method also helps to increase the mass of the wall and
decreases sound transmittance. Pressed bricks may be laid frog down; this method
is favored by the bricklayer, as less mortar is required for bedding. There may
also be a marginal increase in thermal insulation due to the entrapped air. The
disadvantage of this method is that with bricks having very deep V-shaped frog,
there may arise difficulty in creating reliable fixings to the wall when the
fixing hits an air pocket.
Wire-cut bricks may be laid either way up but some types of wire cuts have a
textured (combed) face, creating folds in the face of the bricks, which is
directional. It is recommended to lay these bricks with the folds hanging
downward to maximize the weathering characteristics of the brick.
Ties or cavity ties are use to tie layers of brickwork into one another, to
form a structural whole. A common type is a figure-eight of twisted wire,
usually stainless steel used to prevent corrosion failure. The loop at the end
is buried in the mortar bed as the wall is built up.
Mortar is the mixture of sand, lime and Portland cement mixed with water to a
workable consistency. It is applied with a bricklayer�s trowel and sets solids
in few hours. There are many mixes and admixtures to make mortars with
different performance characteristics.