Traditional solid plaster and render finishes are used both internally and externally. Solid plastering render is often textured or painted on the house. Many older houses are being cement rendered to give their house a modernised look and feel. It also gives important kerb attraction and value to the house. The goal of plaster rendering is two-fold, namely to make the building walls weather resistant and to provide attractive finishes of different textures, says Plaster Wizards – Plasterers in Melbourne. It is compulsory to know the basic principles concerned, that is, how to set up the surface, choose the combine, proportion the equipment and apply the plaster.
The proportions of lime, cement, and sand to apply depend on upon the principle of the plaster rendering and the nature of the building surface area to which plaster is to be applied. A lime plaster is comparatively weak and soft and is slow setting, so it is usually mixed with cement to add to its strength, hardness and to shorten the time of hardening. The quantity of cement, in proportion to the quantity of lime is low and is reduced as much as possible. However, as the proportion of cement is develops the plaster becomes less effective and not easy to apply. The proportion of sand must not exceed three times the merged proportions of cement and lime. The strong plaster should not be applied to a weak spongy backing or a burly finish coat to a poor earlier coat. Some of the best solid hard plasterers in Australia offering creative and innovative plastering solutions like Arte viva often recommend using the best quality materials.
For external building plaster rendering or blueboard rendering on a solid stuff such as cement, dense concrete blocks and solid clay bricks of low porosity, the finest proportions to use are 1 part hydrated lime, 1 part cement and 6 parts sand by amount. On exposed building walls area subject to pouring rains the proportion of lime may be reduced and the cement raised to say 1 ¾:¼: 6 combines or a 1:4 solid cement plaster to which up to 10 percent of lime by mass of the cement is added to make it effective.
On external building surface of high porosity and low strength such as poor class breeze cement blocks, the external rendering should not be stronger than a 1:1:6 mix as over and a burly cement mix with few or without lime should not be used. Not just for homes, but quality office partitions can be moulded into your space with perfect plastering.
The best proportions of internal plastering are 1 cement, 2 lime and 9 sand; or 1 cement, 1 lime and 6 sand; or a lime mix only of 1:3 or 4 be used, remembering that the cement increases the potency and hardness and decreases the period of solidifying.
The weather during plastering & rendering may have substantial pressure on the finished work. External plastering should be started on the shaded side of the building surface to keep it unexposed to the sun as long as likely. Plastering should not be done in frosty weather and plaster hardens slowly in cold weather and a longer period between coats should be endorsed, especially when you’re getting ceiling repairs in Melbourne because the weather down here is really unpredictable. The consecutive coats must be kept damp and protected from drying out in very hot weather. Breeze and local sources of heat may cause too speedy drying out. For plastering, gentle heat and moderate air are the best conditions.