Redecorating an old wall is not always as easy as it sounds. I looked forward to applying an exciting retro design I stumbled upon downtown, but I had no idea that I’d spend the bulk of my time scraping away at the existing paper. Right now, I’m tempted to just paper over the old design that I have already stared at for far too long. But will this have dire consequences?
Lining over wallpaper should only be done if the combination of color, coating, clustering, and condition of the pre-existing wallpaper allows. Otherwise, the lining risks transmitting the old hue, not adhering, and not retaining its texture over time. High-grade lining paper must be used.
The risks involved are worth taking in some contexts. To see what those risks are and whether your is a qualifying situation, let’s delve into the details.
What Is Lining Paper?
Lining paper is paper applied to a wall before painting or wallpapering. It is designed to morph into gaps in the wall, creating a smooth surface for later decoration. This smoothing makes it easier to apply wallpaper or paint and makes for a smoother finish.
The resultant flawless facade makes lining paper a favorite amongst decorators looking to perfect the finish of a roughly dressed interior wall.
Thermal lining paper is a variation that adds heat-preserving material to the liner. The addition reduces energy flow through the wall, which reduces the room warming time.
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FUN FACT: The trapped heat in a thermal lining paper leads to energy-saving benefits, and the increased thickness reduces sound transmission through the wall by up to 35%.
Mold forms on walls whose surface temperature is much colder than room temperature. This difference fosters condensation, which leaves a breeding space for the microbes that make the mold.
Its heating effect closes the temperature gap, making thermal lining effective also in the prevention of mold.
Lining paper comes in different grades, adapted for walls with various conditions. Finer grade lining paper is for walls with a quality finish, whereas rougher grades cater to pitted, knotted, and highly uneven walls. The grades are descriptive of the paper’s weight and thickness:
- 800 – 1000: This is the most common and also the finest. It is best for walls that already have a good finish. It will cover hairline cracks at best. This grade is too delicate for the use case of lining over pre-existing wallpaper.
- 1200 – 1400: This grade is safer for papering over wallpaper in good condition. It can fill small tears, tiny bubbles, and larger cracks.
- 1700 – 2000: This is the heaviest grade and generally only available from specialist stores. Practically, this is the best choice for plastering over wallpaper. Any lighter grade is likelier to show the texture of the underlying paper or wallpaper paste.
Generally, there is no need to size lining paper. The paper will tile over the lined surface. It is important not to overlap adjacent sheets of lining paper as these areas of overlap will create unseemly bulges. Lay the sheets close next to each other.
What Is The ‘Papering-Over’ Problem?
The risks involved in lining over wallpaper derive from four factors of the pre-existing wallpaper:
- Coating: Wallpaper comes in two varieties – vinyl-coated and non-coated. Because vinyl-coated paper is not porous, the lining paper will not stick to it. Layering over it will create space for mold. If the underlying paper has embossing, this will create bumps in the lining. (TIP: If in doubt, rub a wet sponge on a corner of the wallpaper. The moisture will cause the non-coated paper to darken.)
- Condition: Some wallpaper is not designed for humidity. If you are decorating in moist environs, you’re at risk of cultivating mold between the layers. Wallpaper that is already chipped or peeling needs to be removed.
- Color: Dark wallpaper will show through lining paper. This wallpaper must be removed unless the plan is to paint or paper over with a darker color.
- Clustering: The risks of mold and uneven texturing are multiplied when layering over multiple layers of wallpaper. Layering like this should not be done. Unless you’re convinced that there is only one layer underlying, cut away at a corner to reveal the sedimentation.
If you are convinced that you have only a single layer of non-coated wallpaper in good condition with a manageable color, you may proceed to the lining stage. The risks are still extant but manageable.
When To Paper Over Paper
It is recommended that you first remove the existing layers of wallpaper before adding the new lining. If this is deemed too time-consuming and the required finish need not be perfect, you are in a position to risk leaving the existing wallpaper intact.
As discussed, proceed only if you can procure high-grade lining paper.
How To Paper Over Paper
The procedure involves tooling up, prepping, and hanging. It is well within the ability of a first-time DIYer, but care should be taken to manage the underlying surface and hang the lining tightly. Once the surface is prepped, the hanging proceeds as with a normal plastered surface free of wallpaper.
Tools And Equipment
The required kit is available from your local hardware shop. Much of it should be found at home.
- Bucket: You may elect to keep a second for clean water.
- Lining paper: Be sure to pick a grade the suits the job you’re targeting.
- Pasting Brush: Pasting brushes have stiffer bristles. Be sure not to select a soft-bristled painting knife.
- Pasting Surface: A standard wooden table will do.
- Seam Roller.
- Spirit Level: Plumbline is a possible substitute.
- Stanley Knife: (aka box cutter.)
- Tape Measure: A long flat ruler may substitute.
- Wallpaper Brush: This is essential in controlling the material during the hanging phase. An inappropriate brush will increase the risk of a poor finish.
- Wallpaper paste: This comes in different sizes. You need enough to cover the surface area thrice.
There are four easy steps:
Step1: Room Preparation
Disconnect the electrical supply to the room, and use painter’s tape to seal electrical sockets from water incursion. Remove rugs and sensitive movable items—place tarps in anticipation of drip.
Step2: Fix The Wallpaper
Clear the existing wallpaper of imperfections. Tears must be cut and evened. Lumps and bubbles should be sanded down. Remove and clean all nails. Gaps and holes must be plastered.
Ensure that the existing wallpaper is firmly secured. Any loose or peeling areas should be resecured. Clean the walls. First with a duster and then a damp cloth.
Apply a fine layer of sanding to the wallpaper. This will give the primer tooth. With a roller, apply a commercial primer to the area for the lining.
Hang the liner horizontally. Adjacent segments should be lined up with their edges touching, not overlapping.
TIP: Use a seam roller like this one from Amazon. This will prevent peeling at the seams. You could also use a good wallpaper brush (Amazon link) that covers large areas at one time and prevent the formation of air bubbles.
Twelve hours after hanging, the area is ready for emulsion, should you choose to go that route.
Allow a full twenty-four hours of drying before hanging fresh wallpaper. This secures against the risk of the lining paper detaching during the hanging of the wallpaper. If the room is damp and cold, it is safe to lengthen the drying period .
Papering over paper is a matter of taste. In situations that leave room for aesthetic risk-taking and where time is of the essence, there are ways of lining over old wallpaper with reduced chances of regret.
The key is to check the enabling conditions (the four C’s) and get a high-grade paper. Good prepping is essential.