It is difficult to estimate the cost of kerbing, as local questions must interfere, carriage of the material and value of labour entering so largely into the question.
Mr. Codrington[110] states that “A limestone kerb about 1 foot deep and 4 inches wide costs from 2s. 6d. to 3s. 6d. per lineal yard, and a channel 10 inches wide by 6 inches thick rather more.
“Granite kerbs 12 inches wide by 9 inches deep, 6s. 6d. to 7s. per yard run.
“Granite channel 12 inches wide by 6 inches deep, 4s. 6d. per lineal yard.
“A channel 12 inches wide, formed of granite cubes 4 inches by 7 inches, costs about the same.”
I have found that granite kerb 6 by 12 inches could be fixed “in situ” at 3s. 3d. per yard run, and 8 by 12 inches at 4s. 6d. per lineal yard.
Granite channelling composed of 3 courses of granite pitchers 6 by 8 inches, costing 5s. 6d. per lineal yard.
Limestone channelling 15 inches in width by 3 inches in depth, costing 3s. per lineal yard.
A paved channel, gutter, or water table is of the greatest use to a roadway, besides adding greatly to its appearance. Without such a channel the haunches of a road become sadly damaged by the wash of the surface water, which is sometimes so extreme as to undermine the kerb and cause it to fall out.
These channel gutters are made of different materials for macadamised roads, granite setts laid in the direction of the gutter being the best. A channel gutter should not be less than 18 inches wide, so that if made with ordinary 3-inch setts, 6 courses will be necessary; they should be bedded on gravel and well grouted in with lime or cement grouting. Sometimes granite slabs 18 inches wide by 3 or 4 inches thick are used and make an excellent gutter, they are however liable to tip under heavy loads. Limestone slabs can also be used in roads of light traffic with advantage.