Product Attributes

COLOUR DEVELOPMENT IN CLAY BRICK

The colour development in a clay brick, and its permanence, is determined primarily by three factors, namely:

• Chemistry and mineralogy of the clays making up the brick body:
  Typically a clay mix containing ± 2% Fe₂0₃ (Iron Oxide) content will yield a Buff colour brick, whereas a clay with a ± 6% Fe₂0₃ content will fire a Red colour.
• The temperature to which a brick is fired:
  Colour typically changes as the temperature in the kiln rises. For example, when fired at 950° C, a brick from clay containing ± 6% Fe₂0₃ will fire to a Light Red colour but this will become a Dark Red colour at 1,050°C.
• The atmospheric conditions under which a brick is fired:
  A brick made with clay rich in Fe₂0₃ will fire a red colour under oxidizing conditions (plentiful supply of air) but will fire a Blue colour under reducing conditions (lack of oxygen).

The mineral phases formed as a result of the firing process, such as Mullite and Cristobalite, are what ensure that the colours of fired clay bricks will be maintained over the life of clay bricks.

Compressive strength: clay bricks

The figures quoted indicate the minimum to maximum range of individual compressive strengths likely to be recorded for a particular product. The South African Standard Specification for burnt clay masonry units (SABS 227 - 2002) requires that the nominal compressive strength for face bricks be not less than 17.0 Mpa, with individual strengths greater than 12,5 Mpa

Clay Face Brick Classification

FBX – FACE BRICK EXTRA
Clay bricks that are selected or produced for their durability and hight degree of uniformity of size, shape and colour

FBS – FACE BRICK STANDARD
Clay bricks that are selected or produced for their durability and uniformity of size and shape.

FBA – FACE BRICK AESTHETIC
Clay bricks that are selected of produced for their durability and aesthetics effect deriving from non-uniformity of size, shape or colour

FORMAT

	(Length)	(Width)	(Height)
		Horizontal Walling	Parapets
Imperial	222 mm	106 mm	73mm
Coro Maxi 90	222 mm	90 mm	114 mm
Coro Maxi 140	290 mm	140 mm	114 mm
Jem	222 mm	140 mm	73 mm

TOLERANCES ON DIMENSIONS

	FBX	FBS	FBA
Tolerance in work sizes	(L) (W) (H)	(L) (W) (H)	73mm
Individual Unit	5mm ±3mm ±3mm	±7mm ±4mm ±4mm	48-54 bricks/m²
Average Dimension	±2.5mm ±1.5mm ±1.5mm	±3.5mm ±2mm ±2mm	Assume 12mm Joints
Warpage	90% of the units to have warpage of 3mm or less. No unit to exceed 5mm warpage.	No individual unit to exceed 5mm warpage.	No requirements

Product Types

Clay non face bricks
Clay face bricks
Clay pavers
Clay plaster brick walling
Special shaped bricks

Product textures: Clay Face Bricks

Rockface
An irregular rock-like finish on the stretcher face which is achieved by chiselling the brick surface.

Rustic
A crusty finish resembling the bark of a pine or oak tree which accentuates surface shadows

Satin
A smooth, non-grainy face finish

Travertine
A smooth finish with a natural clay grain appearance.