Sanding Bad Plastering [Ultimate Guide]

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If you’ve just bought your dream home and got super excited only to find the property covered in bad plastering, you’re not alone.

A common theme we’re seeing more and more, especially with new builds, is thin, poor, and uneven plastering being churned out in an effort to complete the job as quickly as possible.

So if you’ve found yourself in this situation, you might be wondering what options you have available and if sanding bad plastering is a viable strategy.

In today’s article, we’re going to cover the topic of bad plastering and what you can do to ensure you don’t see any imperfections in your dream home.

Contents hide
1 Signs Of Bad Plastering
2 Examples of Good Plastering
3 Can You Sand Over Bad Plastering?
4 What Sandpaper Should I Use On Plaster?
5 Can Plaster Walls Be Smoothed?

Signs Of Bad Plastering

Some of the key signs of bad plastering include thin plastering that shows the joints of the plasterboards, uneven surfaces and plastering that has gaps around light sockets, skirting boards and door frames.

To help you visualise what this might look like, here are some examples of bad plastering:

The light from this mirror clearly shows how uneven the surface of the wall is.

 

Take note of the gaps between the plastering and the light socket.

 

When exposed to the light of the sun, you can visibly see the joints of the plasterboard. This indicates that the plaster is too thin. Painting on this will inevitably result in cracks appearing as the plaster draws in and releases moisture from the air (resulting in expanding and contracting).

 

Examples of Good Plastering

In an ideal world, your plastering will be sufficiently thick, evenly smooth and connected to light sockets, skirting boards and other joints.

Again, here are some examples of good plastering:

This plastering looks perfectly smooth and joins to the skirting boards without leaving any gaps.

 

Even with a skylight bouncing light onto the surface, there are hardly, if any, imperfections on the surface of this plaster.

 

An example of plastering being perfectly applied around window frames.

Can You Sand Over Bad Plastering?

Yes, it’s perfectly viable to sand over bad plastering but it all depends on how bad the plastering actually is. If there are just a few minor imperfections on the surface, a good rubdown should help. On the other hand, if the surface is completely uneven, there’s not much you can do beyond having a professional skim coating the walls.

What Sandpaper Should I Use On Plaster?

A sandpaper with a P Grit of 50 – 80 is the best sandpaper to even out bad plastering. Bare in mind that it will take a long time by hand and many people looking for a professional finish would be better off using an electric sander such as a Mirka.

Can Plaster Walls Be Smoothed?

If you’ve tried sanding over the bad plastering with minimum success then you might be considering what other options are available to achieve a smooth finish.

One of the simplest and cheapest methods would be to use lining paper to cover the imperfections. Applying lining paper is essentially the same method as regular wallpaper but if you’re not confident enough, you can always get a professional in. Due to the simplicity of the process, it shouldn’t cost too much.

Lining paper could be considered as (literally) papering over the cracks and not fixing the underlying issue. With that in mind, you might want to get a professional plasterer in to deal with the bad plastering, giving you a perfect surface on which to paint or apply wallpaper. Of course, the downside to this is that plasterer’s typically charge high rates so it’s going to be a costly process.

Another option to fix bad plastering is to use EasiFill. This product is a jointing compound and is versatile enough to use to fill holes around sockets or skirting boards but can also be used to smooth out walls.

Here’s a handy video by British Gypsum which shows you exactly how to use EasiFill:

Bear in mind that sanding this product down by hand will produce lots of dust so make sure you use a dustless sander or wear the relevant PPE.