Surface Treatment

SURFACE TREATMENT The surface treatment which a walk receives depends largely upon the practice in the com munity in which the work is being done. The smooth, steel-trowel finish is probably the most common and at the same time the poorest finish used. Such a finish frequently results in crazing or hair-checking of the surface, which is due to nothing more than a slight contraction which takes place in the film formed on the surface by the steel trowel. Besides the smooth finish showing every little blemish and variation in color, it is much more slippery than any of the other finishes.

The wooden-trowel finish is growing in popu larity, and certainly has many points in its favor. The brush finish is similar to the wooden-trowel finish, but it requires an addi tional tool, and one that can be used for no other purpose. The finishes that are produced by special tools, like the tooth-roller, etc., have little to commend them. They are in no way superior to the rough finish produced in a simpler manner, and do not harmonize so well with the usual surroundings.

Marking.

There might possibly be some chance for argument regarding surface finish, but certainly surface marking will not permit of any. The position of the joints between the blocks should be determined before the base is placed, and provided for in the construction.

Positive joints should always be provided in the base of the walk. These are the real joints, and the markings in the top should always occur over them. It is not sufficient to make a surface

marking, together with a feeble effort toward cutting through the base with a small trowel or similar instrument. More walks are disfigured by failure on the part of the builder to provide proper joints than by any other cause.

Size of Block.

The size and shape of the blocks into which a walk is divided are governed very largely by the width of the walk, the local practice, and personal tastes. Other points, however, should be considered; in fact, local practice and personal tastes should be elimi nated entirely when walks on business streets are being constructed. Where the whole space between the building line and the curb is to be covered, many angles and irregular lines are in troduced, owing to openings, steps, etc. Steps should never be constructed over a joint; nor should a joint ever be permitted to intersect a step (excepting at a joint), unless the walk and step are constructed entirely independent of each other. Joints between the blocks should be placed so as to avoid small corners and unneces sary angles; in fact, so far as possible, all blocks should be rectangular. Also the joints in new work, abutting old, should always be projected from the joints in the original work, unless a distinct open joint is provided between the new and the old.