Understanding wall plastering is essential to creating smooth interiors to which paint will adhere. A lot homes in Australia are still finished with plaster and that means that at some point in time, you will need to contract a Sydney plasterer capable of delivering the desired quality and workmanship for your home.
Today, most people are probably more familiar with dry walls but plaster has played and continues to play a very critical role when it comes to finishing walls. The most obvious advantage of plaster is its great versatility, fire resistance and its ability to reduce noise. It has always been the preferred wall covering, particularly if the house has been built using bricks, stone or even frame construction.
Plaster is very pliable and a professional Sydney plasterer can easily manipulate it in order to fit every nook and cranny of your house and deliver a smooth and seamless finishing. A lot of challenging surfaces, as well as wall designs still lend themselves beautifully to plaster finishing.
When plastering, it is recommended that the material be applied in such a way that it adheres to the support wall surface well. It must be able to support its weight without cracking and should deliver a very smooth and hard finish that will make the wall suitable for sandpapering and painting.
Top quality plastering will begin with the lath, where the plaster will be applied. Traditionally, a wooden lath was used but these were unreliable due to the moisture level in the wood, which made it expand and contract, leading to cracks in the plaster. Modern laths are metallic, which are more reliable as they do not retain any moisture. They also provide various spaces on the surface which ensure good adhesion of the plaster.
Plastering is generally done in a three-coat system. This starts with the first two rough coats, which will form the base of the wall. The plaster is formed by a mixture of gypsum or lime, fiber, aggregate and water. The most common aggregate used in rough-coat plaster is sand. The lime used in the plaster can be derived from limestone or in some cases, from crushed oyster shells.
The first coast used in plastering is the scratch coat, which is about 3/8 inch thick. This coat needs to have a rough texture so it is scratched or scored with the use of a com. This is followed by the “brown coat” which has the same mixture as the first coat and is of the same thickness. In this case, it will be left unscoured. The sand in this mixture will instead provide the roughness onto which the finishing coat, which is 1/8 inches, will adhere to.
Achieving the right plaster is, therefore, a very delicate process. If you do not work with a very skilled and knowledgeable Sydney plasterer, you are going to achieve a poor quality plaster that will start cracking sooner. The quality of the plaster work all depend on achieving the right mix and then applying it systematically in order to achieve the desired finish.