Wallpapering a staircase is not as difficult as you might think because the paper is measured, cut, pasted, folded and hung as for any other surface. The difficulty lies in gaining access to considerable heights, so the main thing with this job is that you can reach safely. Never lean over the balustrade to reach walls: hire adjustable ladders specially designed for staircases. A safe, sturdy working base will have its rewards in smoothly hung paper with closely butted edges and accurately trimmed top edges.
1 Identify the longest drop
The first drop of wallpaper you make on a staircase should be the longest. Drop a plumb line and then mark an accurate vertical line on the wall. This will act as the guideline for hanging this and subsequent lengths of wallpaper. Mark the wall with a pencil at intervals down the plumb line then join up the marks with a straight edge to make the vertical guideline. To ensure it is accurate, make a plumb line long enought to hang the entire length of the stairwell.
2 Position the first length
Take your time when you position this first length to make sure that it is vertically true as it will be difficult to correct mistakes later on. Never use the wall as your guide - even in modern homes, they are rarely straight. Instead, always refer to the plumbed line. Paste and hang the first drop to the left of the drawn line, smooth out any air bubbles with a paperhanger's brush and trim off excess. Hang the second drop, butting the edges tightly together.