APPENDIX 3
POLYCHROMATIC BRICKWORK

Notes on the Pricing of Polychromatic Brickwork

As a general rule, the reintroduction of polychromatic brickwork into recent architecture has been associated with underestimation of costs by builders leading to difficulties during construction. Several factors deserve attention.

Architectural Drawings

Clarity and comprehensiveness of architectural drawings incorporating polychromatic brickwork are significant for pricing accuracy.

A strong case can be made for inclusion of all internal and external elevations with polychromatic brickwork. Without full description at tender stage, both builder and subcontractor will underestimate the extent of the work, for example the multiple handling of brick colour pallets. This is a problem which is not overcome by reliance upon an accurate and detailed bill of quantities. Also, any degree of complexity in corbelling, the use of special bricks, header or soldier coursing, and so on, warrants the inclusion of clearly referenced detail drawings. There is a surprising divergence of interpretation in the industry of bricklaying terms.

Specification

Where there is no bill of quantities, the specification must be particularly explicit and, where possible, cross-referenced to detail drawings. For example, the exact location and extent of raked bed joints needs to be clear from the specification when read in conjunction with the drawings, as the raking process is an identifiable extra-over cost for the bricklayer.

Brick gauge for polychromatic brickwork, as has been noted above, often requires a degree of experimentation or "humouring" to arrive at acceptable variations in perpend size between different coloured brick panels. This requires mention in the specification as part of the bricklaying preliminary clauses, or in reference to brick sample panels.

Similarly, if the selected bricks are known to have a higher than usual percentage of imperfections (broken arisses, "banana" distortion, colour variation), the specification needs to draw attention to the need for culling of bricks by either the manufacturer or by the bricklayer. Failure to alert to such culling can lead to unrealistically low wastage rates being assumed by the builder in pricing brick supply.

If mortar is to colour match the selected brick, the specification should deal with whether the matching involves an oxide additive, or the use of a particular sand.

Where flush struck joints are required to be full and free of voids after cutting, some specification guidance will indicate the degree of labour required. For example, striking may be specified as including bagging of struck joints after the joint mortar has stiffened. Bagging should be by styrene foam blocks or approved equal.

Bill of Quantities

The form of tender preferred by most contractors of larger projects is the specified bill - that is a combined document in which quantities follow directly after the specification's detailed descriptions.

A common complaint, even with the specified bill, is that descriptions are either too vague, or are unrelated to the drawings. For example, there is considerable room for error in "banding as per drawings" compared with

"2-course band, stretcher bond in face brick type 2, raked bed joints top and bottom all as per architectural detail drawing 8110/A/101".

Cross referencing between specified bill and drawing greatly reduces the chance of pricing error. During tendering, some contractors only pass on specification and bill to the subcontractor, without drawings. This is a common cause of complaint, and can at least be minimised if specification and drawings are cross-referenced.

The relationship of bricklayer and contractor is often one in which the bricklayer is coerced to "absorb" a lot of brickwork sundry items and items which are arguably extra-overs. Precise descriptions in the specification and in the bill bring objectivity and quantification to this demarcation of costs between contractor and bricklayer subcontractor.

Australian Standard Method of Measurement

The Australian Standard Method of Measurement of Building Works (5th Edition, January 1990) anticipates the measurement of polychromatic brickwork, but leaves broad areas of interpretation and could well be more specific and deserve further detail.

For example, preliminary pricing clauses for brickwork often include:

"Prices for brickwork are to include for square cutting by any method (except as noted in Clauses 7.23 and 7.24 of the Standard Method of Measurement) . . . "

Polychromatic brickwork involving panels where different colour bands meet on a vertical joint invariably lead to more square cutting than is the case in normal face brickwork. Bricklayers often prefer square cutting to be a measured item if the above quoted pricing clause is used. An alternative approach would be for the architect to explain tender documentation of a polychromatic brickwork project with each tenderer, and point out the implications of the polychromatic design in such work as square cutting. Ideally, such discussions would be held by the architect with both contractor and bricklaying subcontractor - but the bricklayer is often not selected during tendering.

Cost Indices for Polychromatic Brickwork

As polychromatic brickwork becomes more prevalent, it would be useful to develop more detailed pricing information.

Several pricing methods were proposed for banded brickwork by subcontractors for a building known to the authors (at June 1991 prices).

(a) Lump sum $25/lineal metre for a coloured band, regardless of width. This reflects the fact that it is the change in brick colour and associated labour in double handling and lost momentum that matters. The extra-over cost is:

Extra over cost for 10 metre band	$25 x 10m2 = $ 250
Total panel cost	$55 x 30m2 = $1650
Cost Index	Banding Extra-Over Total Face Brick Panel	$250 S1650	= 15 %

(b) Another approach proposed was $5 to $10 per square metre extra-over.

	LOW	HIGH
Extra-over cost for 10 metre band	$5 x 30m2	$10 x 30m2
	= $150	= $300
Cost index	$150/$1650	$300/$1650
	9%	18%

(c) A third approach was expressed in terms of reduced productivity. At best, if 600 bricks can be laid in face per man-day, only 450 bricks could be laid in a banded face wall.

The labour rate per thousand could be therefore expressed:

$700 (bricklaying and mortar supply) x 600/450 = $933

Extra over on 30m² wall - This is the extra over arising from the labour rate increase from $700 to $933 per thousand:

30m2 x 50 x	[	($400 brick supply + $933 labour) - ($400 brick supply + $700 labour)	]
		100 bricks
	=	1500 [1333 - 1100]
		1000
	=	1.5 x 233
	=	$349 extra over cost

The above examples do not claim to be definitive, but do illustrate approaches to gather pricing data on polychromatic banded brickwork for cost estimating purposes.

For banded work, a commonly accepted method of measurement for bills is:

(a) Measure total panel in common brickwork:

"110 skin common brickwork" Item 100m²

(b) Extra-over for face brick type FB1(usually the major brick colour type):

"Heading: Face Brick FB1 Extra-over common brickwork for face brickwork in face brick FB1 including change in mortar colour, raked joints, etc." Item 75m²

(c) Extra-over for face brick type FB2:

"Extra-over common brickwork for face brickwork in face brick FB2 including change in mortar colour, etc." Item 25m²

The above procedure avoids the confusion of quantities measured as extra-overs on top of an extra-over.