Wallpaper

A standard roll is fifty-three centimetres wide and ten metres long; it covers about five square metres, but the pattern repeat and cutting allowance reduce that area. The total perimeter of the walls is multiplied by the height, the door and window area is deducted, the result is divided by the roll's net coverage and ten to twenty percent is added for the pattern allowance. Calculating together with the hanger and buying one roll extra is the safe route; a roll bought later can turn out a different shade.

Vinyl papers are washable and resistant to damp; they suit kitchens, hallways and children's rooms. Non-woven (fabric-backed) papers are thicker, hide cracks and small flaws, and are easy to hang and remove; the paste is applied to the wall. Paper-backed products are thinner and more economical, show flaws and can tear when removed. Vinyl in damp and heavily used areas, non-woven in living rooms and bedrooms is a sensible choice.

If the wall is flat, dry and dust-free, yes; but a primer must be applied first. The primer both lets the paste grip the wall evenly and makes the paper easy to remove later. A wall with gloss or oil-based paint should be sanded, and chalking or flaking paint scraped off. Cracks and holes are filled and sanded; paper does not hide flaws, and on thin paper a flaw shows even more. Paper is not hung on a damp wall.

With good workmanship the joins are not visible unless you look closely. A visible join has three causes: the pattern match has slipped, a gap was left where the strips should have been butted edge to edge rather than overlapped, or the paper shrank as it dried. The last comes from too much paste, a wet environment or the paper not being left to soak. On the day of hanging, check the joins in light from the side and show the hanger before accepting the work.