NEW METHODS
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DECORATIVE EXTERIOR
EXTERIOR FINISHES
HEN one considers the number
of people who view the outside of a building compared with the rela- tive few who see its often costly in- terior finishing, a more intensive study of modern means and methods of exterior decoration becomes worth- while.
There is available today a vast range of techniques and materials for exterior finishing. This article is therefore confined to suggesting just a few methods of enhancing the ap- pearance of exterior faces.
It should be stated at the outset that in dealing with the outside of a building it is necessary to combine the general landscape around and be- tween the buildings and any linking elements such as access roads, pedes- trian underpasses and. in some cases, the main entrance sections to large buildings in order to obtain the full advantages of finishing these sections as a complete unit.
Taking concrete as the most ver- satile construction medium, particular- ly in the application of industrialised building techniques, it is now possible
by H. E. Nesling, Building Finishes Ltd. UK
with the use of new materials for forming this plastic compound, to effect considerable exterior improve-
ments.
For the forming of concrete use can now be made of reinforced plas- tics in the form of resin bonded glass fibre. Complex shapes can be pro- duced with the added advantage that reinforced plastic formwork can be used many times.
There is a tendency at the moment for the reinforced plastic to be used as a shutter liner backed up with con- ventional formwork, whereas many advantages could be gained from using the reinforced plastic as a complete form in its own right, the reinforced plastic having much greater strength than is normally recognised.
As a general guide for stiffness, a 3/16 in. thickness of glass fibre is equivalent to 1 16 in. of steel. If this reinforced plastic is then bonded
ZULEL
to some reinforcement, and in this connection much greater use of steel can be made in place of timber, a very strong complete mould can be produced. With the tools available
for the forming of steel channel or angle a complete steel backing frame could be fabricated and then lamin- ated into the glass-fibre mould. If fitted with suitable lugs the reinforced plastic formwork can be removed from the concrete face without any damage to the face of the mould.
Exposed aggregate finishes are being widely used and producing this finish by abrasive blasting often has many advantages over other methods as a very high degree of con- trol is possible. In using these methods it is necessary to design the concrete mix and to be aware of the penetration required to produce a de- corative exposed aggregate finish. In specifying this type of finish careful
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Aerated concrete wall blast-carved by W. G. Mitchell
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Far East Architect & Builder December, 1967