Plastering is often referred to as a type of art, most builders will not attempt a plastering job due to the complex techniques involved – they will normally employ a professional plasterer to undertake the job.
Plastering is a skill that can be learnt quite quickly – by following simple, straightforward guidelines and using the correct tools and plaster mixture.
Firstly, it is important to ensure that the surface is prepped prior to starting. This is a very important stage, the prepping of the surface ensures that there is no damp or dust on the surface and that all wallpaper is removed, if the surface isn’t prepared – you may find that the plaster will not stick to the wall or the plaster may fall off.
Following on from prepping the surface is treated with a mixture of PVA glue and water, this has two main purposes;
To act as a primer for the surface, the PVA glue and water mixture is spread onto the surface to be plastered and the primer is left to dry naturally – this reduces the suction from the wall. If the wall is left untreated – the wall would absorb a high amount of the moisture from the plaster, resulting in the plaster coming away from the wall.
Secondly a solution of PVA and water – mixed to a three parts to one mixture – should be applied prior to the plastering – this allows the plaster to bond to the surface. It is wise to wait until the surface being plastered feels ‘tacky’ to the touch before proceeding with the application of the plaster.
When mixing plaster it is wise to follow some basic instructions. Firstly ensure that the plaster is added to the water and not the other way around. Also, add just enough plaster to the water so that it ‘heaps’ on top of the water – mix this in until the mixture is lump free, then add smaller amounts of the plaster by hand until the mixture is smooth and lump free. Some plasterers describe the consistency of the plaster as melting ice-cream. The most common way of checking the consistency of the plaster is to stand a wooden stick into the mixture – if the stick stands on its own in the mixture – then it’s to the right consistency.
If it’s your first attempt at plastering – it is wise to try a small area first before attempting larger areas. Plastering is a technique where time is important – plaster can go off or become contaminated – so it is essential to have everything in place prior to mixing and applying the plaster.
It is important to clean equipment as you go along to prevent contamination of the plaster – which could result in the plaster falling of the area that is treated.
Plastering essentially is going through the steps of prepping, priming, application of the first coat of plaster (wet trowelling) and then a second coat of plaster when the surface is dry – this is known as dry trowelling. It is important to try and ensure that the surface is smooth and perfectly flat.
This post was supplied by Mark Stubbles, Mark once plastered a kitchen wall by himself but would use a professional if he ever had to do it again.