What is the difference between solid plastering and cement rendering?
Solid plastering is also known as traditional cement rendering in Australia (depending on where you live). Solid plastering implies a greater focus on art and more complex detailing.
Solid plastering, both modern and traditional, is the application of a thin cement-type product consisting of lime, sand, and cement. This render is suitable for claddings such as brick, concrete blocks, stone, and fiber cement sheeting. The render is usually finished with a texture, and it can be painted or pre-coloured after application. It is used mainly on exterior walls, fences in gardens, and interior walls.
Traditions of europe.
For centuries, exterior walls of concrete blocks, bricks, and stone homes have been rendered to enhance their aesthetics and waterproofing. The cement rendering is seen in many different forms throughout Australia, from suburban housing estates to heritage buildings in our cities.
Each country has its own traditional style and colours. In France, for instance, new houses are rendered, and in certain areas, it is mandatory. Local councils also control the range of colors that can be used.
Solid plastering in australia.
Early Australian settlements used solid plastering, and the majority of stone and brick homes were rendered. Australia experienced a resurgence in rendering during the 1950s, especially in federation-style homes.
Simple rendering can transform any house style built from concrete blocks or bricks. A combination of horizontal cladding and brick, or natural stone, is used in many new homes. This gives a modern twist to traditional art.
Combining solid plastering with PVC moldings can create a highly decorative wall finish. Traditional cement render is composed of clean sand and cement, with lime as a finishing agent. However, depending on the desired ‘look,’ renders can be made using fine or coarse sands or have textured or smooth finishes or even colored or natural renders.
With brushes, sponges, squares of carpet, or trowels that are designed for specific finishes, you can create a variety of effects. A professional renderer who is skilled in their craft should be selected to perform traditional solid plastering in auckland. Tradesmen have different styles and skills and can produce both simple and complex decorative effects and texture coatings. Some effects can be achieved by using a thin ‘topcoat’ or a finishing wash.
Engaging a traditional renderer or solid plasterer.
It is best to hire licensed, experienced professionals for cement rendered surfaces. It’s important to research any tradesman before hiring them. You can do this by talking to previous clients, and manufacturers and looking at their work. Be sure to look at the texture of their work and note any cracks or patches. Many Sydney, Brisbane, and Melbourne-based renderers of European descent are experienced in traditional rendering and produce excellent and interesting work.
Ask the plasterer for a sample of the pigmented render and allow it to dry. It is common for pigmented render to dry lighter than wet render. Be aware that pre-coloured renders are difficult to repair since colour matching can be impossible over time due to discoloration from the sun.
Acrylic rendering.
There are many different types of pre-mixed renders that can be used for various situations. For example, “Unitex”, “Rockcote”, and other plasters can be made to stretch in response to changes in temperature or building movement. This is great for new subdivisions.
Pre-mixed acrylic renders are even more water resistant and stronger. They can be applied to a wide range of surfaces including cement blocks, concrete, and AAC paneling. They can be applied to smoother surfaces such as cement sheeting (Blue Board), new high-tech polymer exterior cladding, such as Uni-Base, and expanded Polystyrene. Some of these acrylic pre-mixed renders are smoother than traditional renders and can be sprayed.
Over acrylic render, you can also apply a variety of pigmented acrylic-bound ‘designer coats’. Finishes can be patterned and textured to look like sandstone or marble. They may also have a lime wash, stone chip finish, or clay-like texture. You can choose from stipple finishes, glistening ones, or those with anti-fungal and enhanced water resistance. Acrylic renders dry in just 2 days and cure faster than traditional renders, which take 28 days.
Acrylic renders can produce a wide range of effects. To achieve these, you need a renderer that is familiar with both the product and the style. Clients should ask the manufacturer for recommendations on renderers.
The traditional way to render a room.
1. Surface preparation
If you are working on an internal surface, remove any loose dirt or grease with a hose. If old paint or render is present, it may be necessary to scrape away the old paint and/or roughen up the surface with a wire brush. Otherwise, the render will only adhere for a short period of time. Remove any mould traces with an anti-fungal wash. Otherwise, mould will continue growing and cause ugly patches on your wall.
2. Installing batten guides
Vertical battens are essential for large areas where the surface must be as smooth as it can be.
- Install the battens (50mm wide x 10mm deep) at 1 to 1,5 metre intervals on the wall. This will result in a render that is flat and of equal depth.
- Before rendering, fix the battens with a small amount of silicone filler.
3. Use plaster and texture.
Cement render is composed of:
- Use any general purpose cement with 6 parts of clean, sharp fine sand
- 1 Part Cement
- 1 part Lime. The lime makes the render easier to work with and reduces the cracking of the render when it dries.
- Water to Bind
Read the instructions of the manufacturer before applying the plaster. Different products will have a different drying time. Use a trowel to apply render in sections and smooth the surface. To smooth out the thick render, a large piece of light timber can be placed adjacent to the battens. As you move across the wall, remove battens as you go so that the previous section’s edge becomes the guide for the next section. Materials should generally be mixed well, and only enough should make it to be used within a 30-minute period.
4. Paint
After all sections are rendered and dried, it is finally time to start painting. To increase the adhesion between the paint and the wall, it is recommended that you first apply a bonding agent.
Tips
- Good Weather –Rendering is best done when the weather conditions aren’t extreme. Normal humidity, not too hot nor windy. Avoid working under direct sunlight as much as possible. Make sure the surface is damp but not wet. Spray water on it if needed.
- Multiple Applications – At least two coats of sand are usually required – coarser sand on the first coat and finer sand on the top coat. The first coat should be 10mm thick. Between coats, the cement render should remain slightly moist. After the surface is firm (this may take three days), you can roughen it for the next layer. Two layers of render are usually sufficient. For thicker renders or surfaces that are exposed to extremely wet conditions, a third coat might be needed.
- To prevent cracking – Keep top coat slightly moist for at least 3 days. This will allow the render to cure, and reach its full strength. You don’t want to render it too wet, as it will dry out too quickly and crack. The drying process can be slowed by covering the rendered with plastic sheets.
- Understand the material movement– You should talk to the supplier of the render before committing to a particular product. It is not a good idea to apply a standard render on a brick house because of the way that these two products interact. Cement render contracts constantly when it comes into contact with moisture and heat. Clay bricks are in constant expansion. The render will eventually crack and separate from the brickwork. It is best to use an acrylic render for the brickwork that has clay as a base.
It is possible to apply the rendering as an improvement on existing brick, concrete, or fibre cement houses. The rendering can be used on brick fences to create a uniformed look.