'Can I paint over wallpaper?' an expert reveals what you need to know before wasting money on materials

Asking if you can paint over wallpaper is the one question professional decorators get asked the most – and, it's complicated.

I'm lucky to be able to consult my marvellous Dad, who has been a master painter and decorator for over 50 years, and it is the one question he has been asked a lot over his professional career. 

It would be easy to assume the answer is a resounding yes because the walls have lining paper so surely wallpaper is ok? In essence, the answer is yes but it all depends on the type of wallpaper and the condition of the walls. 

Our trusted, resident expert Paul Kelly (my Dad) explains what you need to know before you start loading up your paintbrushes with the latest interior paint colours to cover the wallpaper trend you no longer wish to live with...

Can you paint over wallpaper? An expert's advice

When painting a room it can feel tempting to paint over outdated wallpaper, but it's not that simple. The answer to whether or not you can paint over wallpaper is essentially yes, but that all depends on the type of paper and the condition it's in.

"As a decorator, I would say to my clients that the age of the wallpaper is essential in determining whether or not I would recommend painting over it," advises Paul. "Because, as a professional, anything over two years I would feel reluctant to do because you can't be sure that it won't bubble." (Bubbling is the term used to describe where the paper begins to lift away from the wall and doesn't go back - forming little air pockets)

"Emulsion dries into paper and therefore if the existing paper has been hung for some time you can reactivate the old paste which is what causes the bubbles," he explains. "As a decorator, you can't guarantee that it won't bubble. The reason it's more troublesome than recently hung paper is that new paste (pasted in under 2 years) is more likely to return to a flat finish, even if it were to bubble."

So unlike the question of whether you should paint skirting boards the same colour as the walls or when you shouldn't paint the ceiling in a colour, the answer is not based on purely aesthetics.

This applies to Anaglypta, embossed Fresco and standard lining papers. While lining paper should be more inclined to take a water-based paint because it's lighter than printed wallpapers and heavy Analypta that often requires tub paste, a much heavier adhesive and therefore is more likely to react.

"Also If the wallpaper is coming away from the wall in the corners or at the seams, or not in very good condition it’s better to remove the wallpaper as opposed to painting over it," he advises.

"You can't paint a vinyl wallpaper, I certainly wouldn't recommend it, because water-based materials (emulsion) will dry and sit on the surface so it doesn't cover the area or adhere to the wall sufficiently." 

Adding: "You also can't/shouldn't paint wallpaper with water damage or mould. All you are doing by painting over these issues is masking a bigger problem."  Signs of dampness or mould would imply an underlying problem and painting over the wall will only hide it for so long and could trap moisture – making it worse in the long run.

Is painting over wallpaper a good idea?

Painting over wallpaper is a good idea if it works because it saves you from stripping the paper and having to make the walls good again – removing the previous paste with a piece of sandpaper to remove any imperfections. If you're relining the walls you'll need to measure up, plumb it and hang the paper. So of course, painting over wallpaper is a good idea to save having to undertake these DIY jobs. But ONLY if the paper proves suitable after testing it.

One way to be sure before wasting money and materials you can paint a small area of one wall to determine if the paper will go 'back' to a pleasing smooth surface. "Be sure to paint over the joints in the paper, because once the edges start lifting you can be pretty certain that you shouldn't paint it and will need to replace it instead."

Paint the test area and let it dry overnight. If it shows signs of bubbling you can feel assured that the paper is in good enough condition to carry on painting.

Can I paint emulsion over wallpaper?

Yes, you can paint emulsion over wallpaper and that's the only recommended paint material to use because it's water-based. "You would generally only use oil-based paints for woodwork and therefore you wouldn't use them on wallpapered areas," says Paul.

Which is the best paint to cover patterned wallpaper?

The best paint to cover patterned wallpaper is emulsion because it's a water-based paint material that is absorbed by the paper. The main factor to consider is how many coats you will need to use to cover the patterned wallpaper. Obviously, a light colour will need more coats compared to decorating with dark colours – like the popular trend for decorating with brown.

In conclusion, you can paint over wallpaper but you need to be sure the paper is in optimum condition before doing so because otherwise you run the risk of wasting a lot of money on decorating materials.