'WARE DAMPNESS

Evening Star, Issue 20134, 26 March 1929, Page 2

'WARE DAMPNESS

POINTS TO SE WATCHED Prevention is always better than cure, and as the subject of damp in the homo is such a vital one to the health of.a]l concerned, every person setting out'to build a new home, particularly one in brick, should have some knowledge of the work that should be put in to prevent dampness (states the ‘Australian Home Beautiful’). It is possible for a builder to skimp many of these things for the sakeof cheapness, but such skimping is little short of a tragedy. If your house is being built under the supervision of an architect, and to bis plans and specifications, these matters will, of course, receive attention; but if the builder is going ahead with no definite detailed instructions, then Ireware.

I,u tho first place you should insist that all the external walls shall be what is known in tho bricklaying trade as “ hollow ” wails—i.e., walls made up of two walls of brick, separated by a cavity., «f ’Btervoning space of about 3in hi width. This is among the very best of preventive measures. Then there are varieties in tho jointing of brickwork, and there have been many arguments among practical men as to whether an overhand or an underhand joint is the batter. Those who favour the latter argue that the ledge formed by tho projecting edge of the lower course permits rain .to soak into the wall; while for the other it is argued that the weathered joint sheds the rain immediately it fails. Uis therefore to be preferred. Damp courses should also be inserted, and these'hre demanded by most of the building regulations nowadays. 'Rliey may bo of the tar and sand variety, or some of tho patent compounds of more recent date. But make sure that they go in. Overhanging eaves are a great protection against driving rain; so arc storm moulds around windows. It is marvellous where rain will penetrate, and.it is often blown in by the wind as it lies on some small ledge. Make your roof gutters largo. Avoid wherever possible’parapets to the walls, for these are a constant source of trouble, necessitating as t-ip.V do the introduction of “box” gutters behind them. Anil the downpipe heads should be so placed as to alloufithe free escape of the water. They should also be protected by wire guards to prevent leaves and rubbish accumulating in them, with consequent blockage and water streaming down the wail, and some finding its way through. Care is necessary at tiie feet of the downpipes also. Here the downpipes should not immediately enter the earthenware pipes which usually carry the water away und?r the footpath to the street channel; but brick pits about 14in square should be provided for the downpipe to discharge into. _ Neglect of this at a property recently inspected had led to the downpipes and the spouting remaining full of water alter every min, and a big settlement of the brickwork at the two front corners of the building. At the conclusion of the job care should be taken to see that there are no broken tiles, especially 'if it lias been necessary for plasterers or others to be on the roof completing work on chimneys, etc., after the tiles have been put on. Accumulations of cement are fraught with danger also. They prevent the rain getting away, and cause trouble. Provide ample ventilation to every paid of your new home, including under floors and in the roof space. _ Condensation is a. very peculiar variety of dampness, and ventilation will prevent dew point being reached. Lack of damp course usually shows hy i stains near the skirting, and a damp chimney breast is due to water soaking through, or to rain settling on projecting brickwork. It even comes down tho Hue itself if proper care is nob given in construction to give it bends. You should not bo able to see light when looking up a chimney. Cement rendering is an excellent protection to walls where the position of some structural feature would make them specially liable to dampness. Portland cement manufacture is now perfected to such a degree that it is now practically waterproof, and of recent years various “ waterproofing compounds ” have been invented, which, when added to the coating of cement, make it absolutely impervious, at little trouble and expense. In treating any surface in this manner see that the joints, are raked out, and that the waterproof cement is about three-quarters of an inch thick, and mixed with not more than three parts of sand. This is almost imperishable. and is a wonderful thing for preventing damp in walls. Don’t allow any sharp internal angles, nevertheless, and give every facility for the water to get away by dripping off (not running down the face of the walls). Cover the work with damp bags lor a few days. It will be much better if it is not allowed to dry too quickly. Care needs also to be taken with the sills of windows—two principal points being to see that they have a good fall to allow the water to get away, and that there is a good drip formed below the sill—the latter to present soakage back into the wall by dropping it down again. , ■Roughcast can be quite good, but

unfortunately in the cheaper class of homes there has been so much scamping that it has.got a bad name. If the preliminary coats are well applied, there is no danger of the water finding its way through, but if they are not properly put on, then they are perforated by the stones and a convenient avenue for the entrance of wet is provided. If you have a basement and the exterior walls come into contact with the ground outside, this is a place that will be prone to dampness. Here internal waterproofed cement rendering is the best. Sometimes asphalt or tar paving is used outside, hut to be successful this requires a dry wall; whereas cement requires a damp surface. This.property of cement is,very valuable, as in most cases it is impossible to dry a newer “ green ” wall in a short time. ire netting may bo stretched along the wall to provide reinforcement