Jul 2021 How to plaster like a professional
Plastering is a pivot in the construction process that hinges on the consistency and patience of the builder. Some may consider it to be advanced DIY but no matter how you see it, plastering gets building projects to the point where the level of the workmanship is clear.
From building a wall to a floor and/or ceiling, the plastering process cannot be skipped or shirked. There are a few reasons for this. One of the biggest is the role that it fills in ensuring good aesthetic value for the structure, as effective plastering fills and covers uneven surfaces in masonry work or blockwork.
The plastering phase is also integral to bolster the integrity of a structure due to its functional jobs. For example, plaster adds to the protection of a structural column or wall from water leakages and fire, and as such, is key to make your structure sustainable.
Sephaku Cement has distilled the process of plastering like a professional into five steps. Follow these guidelines to prepare your surface for the best finish.
Gather materials and tools that will “make it stick”
What do you need for a smooth plastering process? As a start you must prepare your materials and tools upfront. Stock up on Sephaku32 (that already contains limestone or fly ash to assist with adhesion (stickiness), sand, admixtures (if needed) and make sure that you have potable/drinking water close at hand.
You will also require some or all of the following tools:
- Mortar pans
- Metal float
- Measuring tape
- S. corners
- PVC water level tube
- 8m aluminium hollow box
Did you know? One 25kg bag of magnetic plaster will cover five square-metres if applied at 3mm thickness.
Prepare your clean, water sprinkled surface area
Make sure the wall or surface you are plastering is clean and has no loose dust particles on it. If you are working on a ceiling it needs to be made rough by chiselling before you plaster it and you must ensure that all shutter oil or releasing agent used on the shutter work is completely removed.
It is also very important to ensure that all of the building’s electrical work has been completed before you get started because once you have plastered, you close the door to run additional wiring. This consideration covers all of the electrical pipes, boxes and water supply pipes etc. that are fixed according to drawing or requirement.
Also check at this stage that there are no leakages in the wall or surface as plastering should only be done after fixing any of these problems.
Once you have these three checkpoints completed you are nearly ready to get your plaster mix preparation going but remember that when it comes to the surface area, you can sprinkle water on it to help the plaster stick that bit better. In fact, the surface should be well cured for Step 4 so that the wall does not absorb the water from the mix.
Due to efflorescence, a handy tip is to NOT use salty water.
Pull together your perfect-consistency plaster mix
A good plaster mix should be able to be applied in all weather conditions and must adhere to the background/brickwork. It should remain adhered in hot and cold climates. Three different ratios are broadly suggested for your mix: 1:3 for rich mortar for repair work and filling of cracks; 1:4 for external plastering; and 1:5 and 1:6 for internal plaster work.
Many “DIY’ers” ask Google about what the right consistency is for their plaster mix. Some describe the ideal consistency to be “almost creamy” and not too watery, with the advice to add more plaster if this is the case. Others note that your plaster mix must be pliable and durable, which is a “happy-medium” texture, to stop moisture penetrating any gap or crack on your surface while giving your surface a smooth finish.
Another description used for plaster consistency is that it should closely represent “wet cow dung”.
Get started plastering with your base coat
To get your plaster groundwork off from solid ground, it is advised that you make bullhead/level dots that are 2m apart on the surface – and to get plastering you will need to scoop up your plaster mixture onto your trowel and begin by spreading the plaster evenly onto the substrate surface whilst applying firm pressure.
Start at the bottom of the surface if it is a wall and let your highest level of patience and consistency kick in now! The trick is to use smooth strokes for even spreading. One of the great tricks of the trade are to keep your trowel at a slight angle when you apply the plaster as this helps you to avoid getting the trowel stuck on one place.
Apply your best effort in the final coat
In this final step of the finishing process you need to match the thickness with the bullhead/level dots, levelling accordingly using a screed or float. You will need to level the plaster mix between 7mm to 8mm and can always double check the thickness with your plumb bob and line string.
Try to avoid extra trowelling because this can lead to unwanted cracks in the plastered surface. At this point though it is time to clean any splashes of mortar from surrounding fittings and around the finished surface.
Following this you will need to cure the surface, which should be done for three hours over seven days. Be sure to do the curing after 24 hours of completing the plastering.
Now you’re plastering like a professional.