All walls need to be prepared correctly in order to prepare walls for wallpapering. This doesn’t matter whether they are painted or have been previously papered before.
My preference is always to sand the walls prior to any filling or making good.
In order to do that you need to have the right tools. I like to use dustless sanders that extract dust when in use. A dustless sander is simply a sander which is attached to a dust extractor. These dust extractors are designed to filter small particles of dust and have a 3m attachment hose which is very handy
Makita dust extractor for dustless sanding
This allows you to keep the workspace extremely clean and dust free. This is incredibly important when working in a customer’s house and for health and safety reasons.
For large areas like ceilings and walls I like to use an extendable drywall sander. This has a large 225mm sanding head on it and is on an extendable arm, giving you the reach required.
This allows for fast sanding of walls and ceilings.
Fillers to prepare walls for wallpapering
My preference at the moment is to use Gyproc Easi-fill. these come in 5kg or 10kg bags and can be picked up from most of the trade sheds, B&Q, Selco etc…..
Easi-fill is a very smooth finish, doesn’t sag and dries very quickly and is easy to sand down. It is much more cost effective if you have large areas to do.
Make sure you fill your holes, widen out any cracks and fill those. Also make sure that you ‘feather out’ any undulations in the walls.
‘Feathering out’ is basically a wide fill over any lumps and bumps to make the bump or lump less noticeable and smoother across the whole wall.
Once your filler is dry why then you can re-sand the walls once again.
I usually use a 120 grade or lighter depending on how much filler is on the wall. The walls may also need a 2nd fill. The 2nd fill process is very important to achieve a really good finish, do not skip this step.
After the 2nd fill is complete, lightly sand these areas. You now have a prepared wall, ready for sealing.
Using a drywall sander to prepare the walls for papering
Sealing or sizing
The next step is to seal or size your walls.
The walls must be sealed prior to any wallpaper or lining paper going on top. Filler is very dry and if you try to put wallpaper or lining paper on very dry walls, you will have problems.
The best solution for this is to use the paste for putting up the wallcovering.
The paste however, must be thinned out.
You cannot use thick paste on a dry wall. Simply add some water to a bit of the paste and use that as the sealer. Once dry, your walls are now sealed.
The importance of using lining paper to prepare walls for wallpapering
I cannot emphasise enough the importance of using lining paper prior to wallpapering.
But there is one exception though. The only time I’m happy not to use lining paper is if the walls are new, the same colour and I’m using a high quality, non-woven paper.
But for every other circumstance I will always use lining paper on which to hang a finished paper.
It provides a clean surface to work on and It also shows up any undulations you have missed. This allows you to make good with filler over the top of the lining paper prior to wallpapering.
Lining also helps the paper dry evenly and prevents the joins from opening up when the paper shrinks back slightly. Lining paper prevents this.
I have an older post which shows you how to line a wall and splice around a reveal.
Woven and Non-woven papers
What is the difference between woven and non-woven papers?
Woven is traditional wallpaper which you need to apply paste to the back of the wallpaper.
This means you need to be careful not to get paste on the face of the paper and you also need to allow the correct soaking times. This is trickier than a non woven wallpaper.
Non-woven wallpaper is known as ‘paste the wall’ wallpaper. This is a much faster and cleaner installation of the wallpaper. It also means the wallpaper doesn’t shrink back once it dries. Most high quality wallcoverings now ‘paste the wall.’
To use non woven you still need to seal the walls as above. But in order to hang the wallpaper, you paste the wall instead of the back of the paper.
Final Note – make sure you prepare walls for wallpapering correctly
As with all my posts the most important thing to get right is the preparation.
So many people try to skip this step in order to get the job finished quickly.
In the long run, this is a false economy.
You will end up with poor finish and in some cases the project will need to be re-done again. Preparation is key to a successful project.
I like to use the statement ‘prep hard, paint easy’ says it all