Rain and frost canse lime mortar exposed to them to crumble; and the poorer the quality of the mortar the faster it deteri orates.
Many garden walls, the brickwork of which is often inferior to that of the houses to which they belong, show signs of decay at a comparatively early age. The mortar joints begin to gape; and once water has a good lodgment, frost does its work more quickly. A stage will presently be reached it which the wall becomes in effect a pile of loose bricks, kept in position chiefly by their own weight.
Damage due to the mortar losing its facing can be checked only by repointing the joints with fresh mortar – not lime mortar this time, but Portland cement mortar, which is practically imperishable, and, if properly applied, will bond the bricks together where it touches them, besides effectively excluding moisture.
Any amateurs attempt to repoint a wall will have a messy appearance if themethods of the professional bricklayer are not followed. Even if they are, the earliest effort may not be very satisfactory to the eye. But a little practice will bring a rapid improvement; and if the worker takes the precaution of getting his hand in on inconspicuous parts of the brickwork he may be quite pleased with himself when the job is finished.
The first operation is the raking out of the decayed mortar from the joints, to a depth of & inch to ½ inch. In some places the mortar may be hard near the surface, but inch should be the minimum arrived at. The job will be less dirty and unpleasant if the wall is first sprayed with the earden hose, to moisten the mortar. What is raked out should be caught on a board laid along the front of the wall and saved for digging into the garden beds, which will be benefited by the lime in it.
For raking, the worker will need a hook with, its handle part long enough to be grasped by both hands. A large timber dog of I-inch square steel does very well. The raking should be thorough, and the brick be bared at the top and bottom, or sides, as the case may be, of every joint, so that the cement shall have clean brick to grip .
The raking may be done in lengths, if there is a considerable amount of it, alternating with pointing. Periodical change of work will relieve monotony.
The mortar consists of 3 parts fine builders sand to 2 parts cement. After being mixed dry thoroughly, the material should be passed through a sieve of inch mesh, to eliminate any lumps. Sufficient water is then added to make the mortar work easily, without being sloppy.
Since the natural colour of cement is a somewhat staring greyish-white, it may well be toned down, by the addition of vegetable black, to a dark grey, which suits both yellow and red brickwork. The black is added to the cement before the latter is mixed with the sand.
Tests should be made with small quantities, accurately measured, until the mortar, when 24 hours old, has the desired colour, which will be lighter than the wet mixture. When the correct proportions have been established they should be adhered to throughout the job.
For applying the mortar a small bricklayers trowel will be needed; and to hold a pat of mortar close to the work the operator must provide himself with a hawk, a square of wood, 7 inches on the sides, screwed through the centre to a handle 6 inches long.
Filling the Joints
The vertical joints of a length are filled first. Small slices are cut off the flattened pat on the hawk with the back of the trowel and pressed in until a joint is filled. The surface is then smoothed off by a stroke towards one side, and any surplus cut off neatly with the edge of the trowel held vertically. At the top and bottom the mortar will have invaded the horizontal joints, and should be smoothed down by running the tip of the handle along these joints.
At places where the old mortar has been raked out to an abnormal depth, it is advisable to fill in two stages, giving the first application time to set (not harden) before the surfacing coat is added. This applies equally to horizontal joints.
To fill the latter, the hawk is kept close to the work and the trowel used horizontally. At the top it lies back a little under the upper brick, and at the bottom is flush with, or extends slightly beyond, the lower brick.
Joints of this kind keep any water trickling down the wall on the surface. When smoothing down a joint the upper edge of the trowel is therefore pressed in at the top, slightly under the brick.
When the horizontal filling of the length is completed, the top and bottom edges of the joints must be ruled off with a knife and straight-edge. The latter is a batten 3 feet or so long, and 2 ½- to 3 inches deep. On the wall side it has buttons or a strip to hold it away sufficiently to allow it to be tilted for-wards or backwards.
The lower edge of a joint is ruled off just below the corner of the brick and the upper edge a little way under the brick . Some of the surplus mortar will fall away, the rest can be romoved by sweeping the surface with a brush.
It is advisable to damp the brickwork well before applying the mortar, and to keep the wall moist for some days after the mortar has hardened. Dry brick, by sucking the water out of the mortar quickly, weakens the mortars hold.
As in other work for which cement is used, boards and tools must be cleaned thoroughly before being put aside. If the cement is of the quick-setting variety, small mixings are advised until sufficient skill has been acquired to ensure a mixing being used up quickly, or if there is any risk of the work being interrupted for an hour or two.
Ropes, Care of. Fibre ropes, when stored away, should be hung up in a dry, well-ventilated place, out of the reach of rats and mice. If left on a damp floor, they will quickly rot.
A new rope should be well stretched before being passed through blocks, to take the twist out of it.
Before a rope that has been laid by is put into use again, it should be carefully examined, to make sure that it has not suffered any damage.
Soaking a rope in hot creosote or boiled linseed oil will enable it to resist wet, but at the same time reduce its strength. A new undressed rope can bear a load half as heavy again as one that could safely be put on a new dressed rope of the same size. Wet also decreases the strength of a rope, since, like the dressings named, it decreases the friction between the fibres.
A rope should have its ends whipped with twine to prevent them unravelling. To form a whipping, proceed as follows. Turn up one end of the twine and lay it in the rope, pointing towards the tip. Bind several turns over it. Lay a loop of string over the binding, extending as far beyond it as the whipping is to go, and continue wrapping till the loop is almost covered. Cut off the twine, leaving a few inches of spare, and pass it through the loop, which is used to draw it under and out through the binding. Cut off flush.
A rope should never be made fast to an object with sharp angles or rough projections, or passed round a hard corner, without being protected from chafing by soft pads or rounded blocks of wood.
A rope kept in an upper story of a house as an emergency fire-escape should have knots tied in it about a foot apart. This will make the descent of it easier for an inexperienced person.
Wire ropes demand more careful handling than fibre ropes. A kink should never be allowed to form in one, as it will probably do permanent damage. Sharp bends are damaging. A pulley over which a wire rope runs should have a diameter at least 20 times greater than that of the rope.
Rust, the great enemy of ungalvanized wire and steel ropes, can be prevented only by liberal lubrication with oil or grease, which will also make the ropo run mere easily. The lubricant used must be quite free from acid.
Rubbish Destructors. An old water tank, in the bottom and sides of which a large number of holes have been punched inwards, makes a good destructor if supported on brick pillars nine inches high at the corners. Boards stood against the pillars on all but the windward side will promote an upward draught through the contents.
Another suggestion. Build two parallel walls of loose bricks, nine inches thick, two feet apart, and three and a half feet long. Across the walls lay parallel flat iron bars, half an inch apart, and build the brickwork up all round to a height of two feet or more, taking care to bond the bricks well at the corners.
Two of the walls will rest on the ends of the bars; the other two will be carried by bars, which need to be of good strength or supported at intermediate points. The spaces between the bricks may be left open; or be sealed with fireclay, used as mortar during the building.
Brick has advantages over metal in that it does not rust, is burned away more slowly, and retains heat much better.