Common Mistakes When Hanging Wallpaper (Rolls and Pattern Waste)
Wallpaper is the one decorating material you cannot easily top up: a later roll may come from a different print run. A room with 40 ft of wall at 8 ft high and 40 sq ft of openings is 280 sq ft of wall, which takes 12 single rolls of 28 sq ft with 15% waste. The wallpaper calculator does this for your room.
Part of the project planner: Planning to paint a room or a house.
Mistake 1: not allowing for pattern waste
A pattern has to line up at each seam, so some of every strip is thrown away. The bigger the repeat, the more waste:
| Waste allowed | Single rolls | Double rolls |
|---|---|---|
| 10% | 11 | 6 |
| 15% | 12 | 6 |
| 20% | 12 | 6 |
| 25% | 13 | 7 |
Mistake 2: subtracting too much for openings
Taking off every door and window can leave you short, because the strips around them still come from full lengths. Rolls by the area taken off:
| Openings taken off | Single rolls |
|---|---|
| 0 sq ft | 14 |
| 20 sq ft | 13 |
| 40 sq ft | 12 |
| 60 sq ft | 11 |
When in doubt, take off less, not more.
Mistake 3: mixing up roll sizes
Rolls are sold in different coverages, and some are sold as double rolls. Check the area on the label. For the same room:
| Coverage per roll | Rolls |
|---|---|
| 20 sq ft | 17 |
| 28 sq ft | 12 |
| 56 sq ft | 6 |
Mistake 4: skipping the wall prep
- Fill holes, sand, and clean the wall, and prime it so that the paste does not soak in.
- Remove old paper first: new paper over loose old paper will lift.
- Mark a true vertical line for the first strip with a level, since the corner of the room is rarely straight.
Mistake 5: hanging it wrong
- Check each strip against the one before for matching, before you cut.
- Cut strips a few inches long and trim at the top and bottom after hanging.
- Smooth from the middle out, and wipe paste off the face straight away.
- Keep the leftover rolls for repairs.
Paint is easier if you are unsure: see the paint calculator. Estimates only: check the repeat and coverage on the roll you choose.
Frequently asked questions
How many rolls of wallpaper do I need?
A room with 40 ft of wall at 8 ft high with 40 sq ft of openings needs about 12 single rolls (6 double rolls) at 15% waste.
Why do rolls of the same pattern need to match?
Rolls from different print runs can vary in shade. Check the batch number and buy all the rolls at once.
What is pattern repeat?
It is the distance before the design repeats. A large repeat means you cut more waste, so allow extra, 20 to 25 percent for a big pattern.
Do I paint or paper first?
Paint the ceiling and trim first, then hang paper. Prepare walls by filling and sanding, and use a lining paper or primer if the walls are rough.
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Estimates only. Quantities depend on your materials, site and supplier. Confirm important numbers before you order, and follow local building codes for anything structural.