What’s Involved in Plastering a Room?
- Protecting the Room
The first thing that a professional plasterer should do is lay down dust sheets to protect your floor and other furnishings. This will also collect any debris while also preventing it from sticking it to the plaster in order to provide a smooth and clean surface.
- Removing Old Plaster
Once the dust sheets are set out, the plasterer will then proceed to remove any old plaster rather than just re-plastering as this will ensure it is longer-lasting. To do this, they may use a drill or a chisel and hammer to prevent any damage to the walls.
- Priming the Walls
After all the old plaster is removed along with any dirt and debris, the tradesman will then begin to prime the walls. This will involve diluting and brushing PVA onto to the wall, which will enable your plaster to be applied immediately and also allow it to dry out evenly.
- Mixing the Plaster
Most plasterers will mix their plaster on-site. They may choose a traditional plastering technique which involves a smooth wet mix of either gypsum or cement and water which is spread directly onto the wall using a trowel then finished with a thin skin coat of gypsum.
Most homeowners prefer wet plaster as it offers a smooth and durable finish, but you can also consider dry-lining. Dry-lining uses manufactured boards of paper-covered plasterboards which are nailed or screwed in place. It is a lot quicker to put up, doesn’t need to dry out, and there is little risk of any cracking.
- Applying the Plaster
Modern plaster is typically applied to walls in 2 coats in order to adequately replace the existing plaster. The first coat is to take up any discrepancies in the wall and present a reasonably flat surface for the second coat.
They will usually apply small amounts of plaster using a hawk board, trowel and float which helps to spread out the plaster evenly. The most popular method involves plastering a small amount of wall then moving on until the entire wall is covered.
- Skimming and Smoothing
Once the first coat of plaster has been applied, they will then wait around 20 minutes to allow it to dry slightly. After this time, they will use the trowel to even out any bumps while also smoothing out the corners at the top and bottom of the wall.
- Scraping the Surface
Some plasterers skip this part; however, it can be beneficial to ensure an entirely smooth surface. Scraping the surface involves the use of a devilling float which is basically a piece of wood with nails which works to get rid of small lumps.
- Applying Another Layer
Once you’ve smoothed out any bumps, you should check that the first layer of plaster is dry before applying another. The second coat uses finish plaster which is slightly thinner than the first layer and when applied by a good plasterer will leave a perfectly flat and smooth wall.
- Finishing Up
To finish off the plasterwork, the tradesman will wait around two minutes before spraying the edges with water and running over the surface with a trowel or wet brush. When set, the plaster forms an integral part of the wall and can be covered with paint or wallpaper.