BUILDING AND HOMES

Dominion, Volume 24, Issue 110, 3 February 1931, Page 14

BUILDING AND HOMES

(By ‘

MAGNESIA STUCCO

New Finishing Material

EXTERIOR DECORATION The following interesting notes .on magnesia stucco, a material that is coming into favour in Great Britain and elsewhere for the external finishing of buildings, were contributed by Mr. G. Hall to the "illustrated Carpenter and Builder”: — Magnesia stucco is of comparatively recent origin, and, like a great many other new ideas, it. has had to overcome prejudice due to ignorance, exploitation, and misapplication. Now it has established itself and earned recognition as a stable construction material, it has in consequence come into greater prominence. Its chief use is in the form of exterior stucco, and by far the greater proportion of magnesia cements are used in this form. When properly applied over a suitable backing, it lends itself to the expression of ideas, both artistically and architecturally, in a manner unsurpassed by other building materials. ’To be certain of making the best use of this material it should be applied according to very definite specifications. When this stucco was comparatively new, the high early strengths obtainable led to the inference that almost any method of application would be good enough. The experience of the early workers who used magnesia stucco showed that certain rules bad to be followed, and certain precautions had to be taken, with this as with any other plastic material, to ensure that the best results would be obtained. Where it is intended to use stucco, the building should be constructed for its reception; in other words, its employment should begin with the foundations. The provision of ample space for footings is accessary, and any tendency that might result in the cracking of the stucco should be eliminated. Such a tendency is the movement of the walls, and this can be overcome by providing diagonal bracing for the walls, floors, and ceilings. Built-up corner posts, double studding beside doors- and windows, and double headers over doors and windows, all ensure against cracked walls. • Chimneys need a great deal of care. The best remedy against cracking, attendant upon settling, is the provision of oversize footings. *, , Wood and Metal Laths.

The backing for the stucco should be carefully considered. Where it is desired to use wood laths, then only the best grade of white pine, short leaf yellow pine, cypress, or redwood should be used. No cross-grained wood or any other kind of lath that is susceptible to warping should be employed. The spacing of the laths should be about -Jin., and thev should be nailed with galvanised nails. To give the stucco a good key, the laths should be furred up from the surface on about ISin. centres to a depth of about Jin. The laths should always lie placed horizontally, and the joints broken at every eighth lath. Metal lathing is sometimes used as a backing for stucco. The best of such material is galvanised copper, or else a copper-plated steel lath that has been treated with an anti-corrosive paint. The joints, where metal lathing is employed, should be well overlapped, and the whole securely fastened to the sheathing. It is good practice to use hollow tiles for backing, but they should always be rough or grooved, and never smooth or glazed. No lime should be used in the mortar that is employed in the layingup of such backing. This is very important, because of the detrimental chemical action which takes place between lime and the magnesium chloride of the stucco. It is infinitely better practice to use a plastic magnesia cement as mortar for the laying-up of tiles, since it possesses great strength and does not freeze when employed in winter construction work. , , . iii Materials for stuceo backings should be rejected unless they fulfil two important conditions. They, should be able to afford a good mechanical key for the stucco and should not be susceptible to warping or disintegration due to adverse atmospheric conditions. It is mjt a good plan to.use magnesm stucco as a surface on exterior cornices and the like. but. when it is considered desirable to do so, the cornice should first be covered with galvanised iron wire mesh and the stucco applied to a thickness of lin. It is of primary importance to ensure that where stucco is employed no water shall, percolate through the surface. If it does so, the damage it may cause is almost unlimited. It may warp the sheathing and crack the finish, discolour the surface, and by freezing and subsequent thawing it may break the. bond between the plaster and the backing. -t may also rot the sheathing and penetrate ami discolour the interior plaster. These things are very serious, but they may be prevented by applying flashing at the critical points. Generally, all exposed edges of stuceo slab should be flashed. No water should be allow.ed to flow over the surface of the stucco. This very often happens when water collects on sills. In such a case as this a water stop should be provided, so that the water will flow quite clear of the wall and not leave unsightly streaks. Mixing Methods. The mixing of the stucco requires a certain amount of care. It should never be mixed in a box in which lime, gypsum, or Portland cement has been mixed. A very convenient strength for the magnesium chloride solution for use on the job is 22 degrees Beaume. Re-tempering of mixed-up material should never be permitted. The consistency deemed desirable shall be considered to have been achieved only after three minutes’ continuous stirring without further addition of gauging liquid. The application of stucco to an absorptive backing should follow a wetting of the latter with the gauging liquid of the stucco. This should be done a minute or two previous to the application of the stucco. Walls that are wet with rainwater, or that are considered likely to contain frozen moisture, are not. in a suitable condition for the application of stucco. .... . , The stucco is best applied in two layers. The first, or base, coat should be about jin. 'thick, and should be roughened just before it sets hard. The second, or top coat, which can be applied at any time after the undercoat has obtained its initial set, should also be Jin. thick. Where a considerable time has elapsed between the application of the two coats, , the surface of the undercoat should be wetted just the same as though it were backing. Stucco Finishes.

There are many finishes that can be applied to stucco. If pebbledash is to be applied to the surface, the stones should be thrown into the soft coat from a wide spade, but great care must be taken to apply the pebbles evenly, or else there will be “sweep” marks that would mar the colour and symmetry of the surface. The stones should be pressed evenly into the surface, while the stucco is soft. Before throwing the pebbles into the stueeo, they should be well sifted or screened, to get a uniformity of size and to remove dust and fine particles. In some cases the finish is applied as a liquid in the form of paint, which can be sprayed on to the stucco. This treatment renders possible a uniformity of colour and density that cannot be obtained by other methods. The spray painting of pebble-coated stucco results in a coloured roughly-textured surface that can be particularly attractive. Spray painting is, of course, a very good means of renovating old stucco, since, like any other exterior surface, stucco collects dirt and soot.

“JACK PLANE.")

STRAY NOTES

Furnishing for the Family The home should be furnished in, such a way that each member of the family, each generation, can secure the maximum happiness and comfort. A furnishing scheme may be a picture of perfect artistry, in which every principle and every rule has been careffilly studied. Biit if it is merely a scheme, a picture which must be looked at and handled with great care for fear it should spoil, it is obviously failing in its object. The home is made for the family, not the family for the home. In the first place, if there are kiddies in the family, the large living-room is of more importance than the large bedroom. This means that if each junior member of the family has a bedroom, however small, and provided those bedrooms give plenty of fresh air and healthy sleep, the greatest importance attaches to the living-room. • Mow should we set about to furnish a living-room for the family? First of all, let us see that our carpet is of the hardest-wearing quality, and that a thick underfelt is used beneath to give even longer and softer wear. Brussels quality carpets are probably the hardestwearing of all, but a fine quality Wilton will stand any amount of hard treatment. If there is a young family, such light woods as weathered oak would be better in the dining-room. For dirty, sticky and damp fingers during playtime will stain the pieces badly, whereas at meal times, when hands must be thoroughly washed

and the junior must be disciplined in good behaviour, the weathered oak will not be badly treated. On the other hand, there are types of weathered oak furniture which are of a slightly darker colour, so that handmarks will not show.

A dark shade of walnut, mahogany or, for the old-world type of room, oak are all good for such family furnishing. . . .

To see that the fender is solid is another good precaution, for youngsters of all ages have a habit of standing with their backs to the fire and their heels denting the curb. But most important of all. let us look to our upholstered easy chairs and settees if family life is to be full of comfort and carc-free ease. Upholstered furniture which is cheap but which has a pleasing exterior is sometimes misleading. For the inner construction is the most important factor, and it is far better to pay a little more and ensure your chairs and settee being made well and strongly. II To jump or nose-dive ou to the settee. as kiddies will, or continually lo sit down heavily and suddenly upon a chair, as even grown-ups will do, tests the strength of any upholstery. It is the steel support, not ordinary webbing, that will stand the test, while steel lace-web springing will withstand the hardest usage.

Equally important is the arranging of the room. Do not be afraid to leave plenty of space in the centre of the room. While children’s bedrooms can be small, they should have plenty of light. Even a room in the roof frequently finds favour, and the disadvantage of being too warm during the hot days can be counteracted' by using asbestos sheets over the ceiling. But the actual furnishing should bo simple in the extreme. Furniture of natural-coloured wood (not limed) is probably the best, for dirty marks are easily seen and soon remedied. A small 3ft. 6in. wardrobe is necessary, also a chest of drawers, which, if fitted with a mirror, can serve as the dressing-table.

I The counteracting of India’s rigorous I summer conditions by a system of apartment blocks fitted with cooling apparatus was urged by C. A. John Hendry, a pioneer in cooling apparatus, in a broadcast address from Calcutta recently. “It is surprising.” he said, "that apart from an already obsolete fan there has been no attempt to mitigate the hot and humid climate. Only a theatre and one or two legislative buildings have been equipped with cooling installations, although such things have been common in America for years.” Mr. Hendry predicted that “with the introduction of air-cooled buildisgr our struetqxefi will entirely change. The buildings of the wealthy will still remain isolated, but the ordinary man will live in great blocks of lints, designed for economical cooling, and when he enters he will shut out the glare and discomfort of the tropics and will enter an atmosphere approximating to temperate conditions.”