Wallpaper Paste
How Much Wallpaper Paste Do You Need?
Wallpaper paste is the part of a project people routinely forget to measure. Most guidance says "use one packet per X rolls" and leaves it there. The actual answer depends on whether you're paste-the-paper or paste-the-wall, how absorbent the wall is, and how much the paste is diluted — and getting it wrong mid-job means either a dry stop or a trip back to the shop. Here's how to work out what you actually need.
Open the Wallpaper PlannerCheck whether your paper is paste-the-paper or paste-the-wall
Paste-the-paper means the adhesive goes on the back of each strip; paste-the-wall means the adhesive goes on the wall and the strip is applied dry. The two methods use different concentrations and different quantities — a paste-the-wall job typically uses less adhesive per square metre because you're pasting only what you need for each strip as you go, without paste left on the table. The paper's label or spec sheet will tell you which method is suitable.
Read the packet's coverage figure before you mix
Powdered paste packets state a roll coverage on the side — commonly something like "sufficient for 4–6 rolls of standard paper." That figure assumes a dilution ratio and a paper type; a thick or heavyweight wallpaper soaks up more adhesive and brings the coverage towards the lower end of the range. Mix slightly stronger (less water) for heavy papers, slightly weaker (more water) for thin or lightweight papers.
Porous or bare walls absorb more paste
An unpainted or newly plastered wall soaks up the first application of paste far more quickly than a wall that already has a coat of paint or lining paper. On an absorbent surface, apply a size coat (a heavily diluted paste wash) and let it dry before hanging — this seals the surface and lets each strip's pasted side adhere to the wall rather than to the wall soaking the adhesive away from the paper.
Calculate on rolls, not square metres
The easiest approach: look at your roll count for the job, check the packet's coverage range, and divide. If a packet covers 4–6 rolls and you're hanging 9 rolls of heavyweight paper, buy three packets (covering 12 rolls at the lower-end figure, with one packet as buffer). Buy to the lower end of the coverage range unless you know the paper is lightweight.
Mix fresh for each session, not for the whole job upfront
Wallpaper paste that sits mixed for more than a few hours starts to lose tack, especially in warm weather. If the job spans more than one day, mix only as much as you can use in a few hours each session. Label packets clearly so you know how much is left, and keep the bag sealed between sessions to prevent drying and contamination.
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See plans & pricingCommon questions
Can I use the same paste for every type of wallpaper?
Not always — heavyweight vinyl wallpapers and non-woven papers sometimes specify a heavy-duty adhesive or a specific brand of paste-the-wall adhesive rather than standard powder paste. Check the product's hanging instructions rather than assuming a general-purpose paste will work.
Does it matter if the paste is slightly too thin or too thick?
Thin paste reduces tack and can let strips slip or peel at the seams before the adhesive sets, especially on heavier papers. Too thick and the paste is hard to spread evenly and takes longer to set. Mix to the packet's recommended ratio for the paper weight, and test the first strip's hold before papering the whole room.
How soon after mixing can I start hanging?
Most powder pastes need 5–10 minutes after mixing to fully hydrate and reach the right consistency — the paste should be smooth and slightly gelatinous, with no dry lumps. Hanging with paste that has not fully dissolved can leave lumps under the paper that show through once dry.
More wallpaper guides
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Open the Wallpaper PlannerPlanning a specific room? See how much wallpaper you need →
Quoting this as a job, not a DIY project? Try the contractor estimator →
Working out how many rolls you need before you buy paste? Try the wallpaper calculator →
Hanging in a tricky space like a stairwell? How to hang wallpaper in a stairwell →
Matching your wallpaper pattern? How to match wallpaper patterns →