Can you imagine a birthday party without a cake? Well, it is definitely hard to imagine. Same goes with Plastering. Constructing a project without plastering is impossible.
Plastering is a process in which rough surfaces of a wall or ceiling roofs are changed or rendered to provide smoothness. The main purpose of plastering is to obtain a hard and smooth surface that could be further painted to give a nice pleasant appearance.
There are different types of plastering used in accordance with the material used in it. If you work in the construction or architecture industry, you should definitely have a knowledge about the different types of plaster. If you want to get your plastering work done, just check out www.myplasterersmelbourne.com/ and I am sure they will not disappoint you. You will understand that yourself if you just go through their website once.
Let’s dive into different types of plaster used :
- Plastering- the step-by-step guide
- Frequently Asked Questions
Lime plaster is a mixture of three important components i.e, sand, water and lime. This mixture is not only used for under coat but sometimes also used as finish coat.
When we talk about lime plaster, we refer to non-hydraulic lime which may be referred to as hot lime, fat lime or lime putty. Lime plaster can also be used for ancient structure restoration or rehabilitation.
Benefits of lime plaster :
- Lime plaster contains high pH which prevents fungus. wLime plaster made up from lime is less brittle and less prone to cracking than cement plaster.
- Lime plaster is least affected by water and will not soften like drywall.
- Lime plaster is known to be permeable and allows for the diffusion and evaporation of moisture.
- Lime plaster is also durable to be used as a lime render on the exterior of the buildings.
Cement plaster is a mixture of plaster, sand, portland cement and water which is generally applied to masonry interiors and exteriors to achieve a smooth surface. Various cement- based plasters are often used as proprietary spray fireproofing products.
Benefits of cement plaster :
- Cement plaster coating creates a stronger and extra durable wall finish
- Cement plaster can be used on both external or internal surfaces
- Cement plaster is not a rust inhibitor
- Cement plaster has more or less thermal conductivity
- Cement plaster has more or less identical acoustics properties.
Gypsum is known to be a soft sulphate mineral composed of Calcium sulphate dihydrate. It is commonly used as a fertiliser, in sculptures as plaster materials.
When dry POP powder is mixed with water it gets hard, this mixture when applied over bricks, blocks concrete surfaces to form a surface which are called Gypsum plasters.
In recent times, gypsum has proved to be a miraculous material aiding interior construction due to its amazing properties.
Benefits of Gypsum plasters :
- Gypsum plaster saves construction time.
- Gypsum plaster has a lower impact on the environment.
- Gypsum plaster incurs low water usages
- Gypsum plaster eliminates shrinkage cracks
- Gypsum plaster also offers ease of application.
Mud plaster is made from a mixture of heavy clay and water. Mud plaster is generally applied in two coats.
For mud plaster, the surface has to be prepared in exactly the same manner as lime and cement plaster. It provides protection to structural and building components as well as colour and texture.
Benefits of mud plaster :
- Mud plaster gives a smooth and stunning look to the walls.
- Mud plaster is also known to be environmentally friendly.
- They are known to be less toxic compared to other plasters
- The repairing work of mud plaster is also very easy and inexpensive.
To sum up, these are 4 different types of plastering which have their own characteristics and usage. Among these, lime and cement plasters are the highly used one.Choose as per your requirement and get the plastering work of your construction project done just like the way how you want it!
Plastering- the step-by-step guide
Plastering is a highly technical process and you should leave it to the professionals most of the time. However, you can also try it for small projects, but you need to follow the steps accordingly. Make sure you use thick and freshly mixed plaster.
Prepare the work area and materials
1. Have clean tools
Even if you don’t know, you need to avoid contamination when plastering. Don’t mix the plaster, but make sure that all the floats, trowels, buckets, and everything else that touches the wall are impeccable. Even the most minor stain of plaster leftover from a previous job can alter the plaster’s ability to stick/set correctly. If you want the plaster to set slowly, use cold water and allow it to soak and mix as little as possible. When you want the plaster to set quickly, use hot water instead.
2. Keep the work area clean
Use cheap canvas sheeting or some plastic tarps to protect against spills, dust, and muddy footprints. Plastering can get messy and you don’t want to spend hours cleaning. Also, plaster is difficult to clean off dark walls.
Consider these aspects as well:
- Plaster may damage/scratch laminate and wood floors
- Use painter’s tape to have airtight protection
- Remove the cloths when you’re done and clean them outside the house
- Plaster falling off the tools is the leading cause of the mess.
3. Remove dust and debris off the walls
Use a dry stiff-bristled brush to scrub the walls from top to bottom. Don’t skip areas with buildup or with stripped layers of old plaster. Use a damp cloth to pick up the dirt when you’re done. You will also need to:
- Repair cracks in the wall before plastering
- Prime over stained areas to improve adherence of plaster
- Seek that the wall and ceilings are flush and plumb before plastering
- Dust, oil, soap, mold, and tar can impede plaster from adhering to the surface, so always clean first.
4. Brush on PVA glue
Add four parts of water and one part PVA glue to help the wall hold the plaster. Brush/roll the PVA over the whole wall and make sure to cover it entirely. You need to apply the plaster while the PVA coat is tacky and not completely dry. You will also reduce the risk of leaching moisture from the plaster, which typically causes crumbling.
5. Mix plaster
Use a five or 7-gallon bucket to mix the plaster. Fill half the bucket with cool and clean water. Shake a new bag of plaster mix and add it to the bucket until you get a mound above the water’s surface. Use a stirring rod/plunger to mix it well.
- Always add the plaster mix to the water and not the other way around. Stir the mixture as you add in the plaster.
- Use an electric drill with a paddle attachment to work quicker. Mixing the plaster this way will make it set quicker. For small patchwork, use a small bucket and a mix by hand so that the plaster sets slow and you have time to finish.
6. Stir the plaster continuously
You should mix until it’s smooth and has no more lumps. Scrape the sides of the bucket from time to time to loosen dry pockets. The final plaster should have a peanut butter consistency. Stick a wooden paint stirrer down into the bucket. You’re ready to use the plaster if the stirrer stands on its own.
Apply the first coat of plaster
1. Put some fresh plaster onto the hawk board
Use the edge of the trowel to scoop the plaster out of the bucket. Pile it on so you don’t need to stop to add more. If the plaster has the proper consistency, it shouldn’t stick to the hawk. Wet the hawk a bit to ease out the release.
2. Work with a small amount of plaster
Slide the flat edge of the trowel under the plaster’s end and take only to layer a strip from top to bottom. The plaster should sit right in the trowel’s center. Begin with a small amount of plaster and add as you go. It’s easier to build the coat than to even out a large amount.
3. Smear the plaster onto the walls
Push the plaster up the wall with a gentle arc and stand to reach higher parts. Slide the trowel over 2-3 inches at the top of the stroke and reverse your motion. Smooth the plaster from time to time using the same method.
- Maintain the trowel at a slight angle.
- If the plaster is soft and slides down, allow it 5 minutes to harden. Hit it with the trowel afterward and see that it no longer slips.
- The first coat should be 3/8” in thick
4. Plaster the wall in sections
Spread the plaster from bottom to top and stop to get more plaster onto the hawk board. Do it until you spread the plaster evenly over the whole surface.
- Get a ladder to get at the upper corners
- You will come back later to smooth and polish, so don’t worry about the thickness.
5. Smooth the first coat of plaster
Clear the trowel after applying the plaster and run it over the wall in every direction. Use enough pressure and insist on areas where the plaster is thick. It’s like you’re icing the cake.
- You can re-wet the first sections of the plaster with a spray bottle. You will obtain better results.
- Use a high-quality paintbrush for the edges and corners.
6. Scrape the plaster to create texture
Score the wet plaster to obtain a good base for the second coat. Use a notched trowel or a deviling float to rake the plaster vertically from one end to the other. This way, you will no longer worry about separating or cracking.
Also, scoring leads to shallow grooves that help the second coat adhere better and enhance the overall surface.
Spreading and polishing
1. Spread on the second and final coat of plaster
The outer coat should be 3/8”, but you can have good results with 1/12” in as well. You apply the final coat the same way you applied the first coat; see that you don’t have any seams or gaps. Use the trowel/float to do the final touches.
2. Get the even finish
Glide afloat over the surface of the wet plaster in all directions to eliminate the holes, lines, lumps, and inconsistencies in thickness. Aim for a smooth and even appearance. Don’t rush in the smoothing of the plaster.
Pay attention not to polish the plaster too much as you can weaken the hold of wallpaper or paint.
3. Let the plaster set
It can take 2 to 5 days for plaster to harden completely. Try not to handle fresh plaster while drying. The imperfections that can occur during drying will be easy to notice after the plaster has dried.
The temperature of the work area, the composition of the plaster, and the amount of moisture in the air will affect the drying time. Make sure that the wall is completely dry before you add the wallpaper, paint, or any other decorations.
Frequently Asked Questions
What is the process of plastering?
Plastering is the process of covering rough walls and uneven surfaces when building houses and structures with plastic material (plaster). The latter is a mixture of cement, concrete, or lime and sand with the appropriate amount of water.
Is it difficult to plaster?
Plastering requires skills, experience, accuracy, and care to obtain the most long-lasting and perfect results. It doesn’t mean that you cannot try DIY plastering. However, you need to do due diligence about the process.
How long will plastering a ceiling will take?
Plastering a small ceiling can last between 6 to 12 hours, whereas a medium-sized ceiling will take 8-12 hours. You will spend 2-3 days plastering a large ceiling.
Plastering is important. Why is so?
When you plaster, you create a long-lasting and durable finish to existing drywall. As water escapes from the cement mixture, a chemical reaction occurs. The response strengthens the bond, which makes the plastered walls strong. Plastering also creates an even surface for the paint and wallpaper.
Is there a difference between plastering and skimming?
Both plastering and skimming are used to improve the durability of a wall and decorate walls. However, skimming will update an old building, whereas plastering is for a new one. Additionally, the plastered areas are rough, whereas the skimmed surfaces are smooth.
How can you tell if the plaster is dry or not?
You have to observe the change of color to figure out if the plastered has dried or not. Dry plaster has an even pale pink complexion—simply examine its color to decide if it has dried.