Estimating quantity Measure the height of the room from the skirting to the picture rail or ceiling and also the distance around the walls, including doors and windows. Check to see how many rolls of wallpaper you need. If your measurement for the distance around the room falls between two measurements on the chart, use the larger figure. Basic measurements will be sufficient for plain or free match papers. Where you need to match the pattern you must allow for wastage at the foot of each length according to the depth of the repeat; usually an extra roll for every five is enough, although you may need to allow extra if the repeat pattern is very deep. Extra paper will also be needed if the room has recesses or projections since the pattern should be centred on these to give a balanced look.
Buying the paper
Most wall coverings are sold in rolls 10m long and 520mm wide. They are normally supplied ready-trimmed, but if you do select a paper with margins ask your supplier to trim them for you – don’t attempt it yourself. Wallpaper is printed in batches and the colour may vary from batch to batch; make sure every roll you buy bears the same batch number. It is worth buying an extra roll at the outset since you may have trouble obtaining another roll of the same batch later on. Check if you can buy a spare roll on a sale-or-return basis. If you realize halfway through a job that you will not have sufficient paper and you cannot buy another roll from the same batch, use the odd roll in an area where any colour variation will not be so noticeable, such as on a short wall or in a recess. Unfortunately even corresponding batch numbers do not always guarantee an exact colour match. Before hanging the paper inspect the rolls in a good light; if you spot any shade differences, decide the best sequence for hanging. Imperfections in the paper itself can be eliminated when you cut the paper into lengths. But if you find inconsistencies in the pattern take the roll back to your supplier, since you will have a lot of wastage if you try to eliminate ‘repeat’ defects. If after hanging the paper you find the pattern on adjoining lengths will not align, it is probably the result of not soaking the rolls with paste for the same length of time or stretching the paper when putting it up.
Storing wallpaper
Always store rolls of wallpaper flat; never stand them on end or you will damage the edges and make it difficult to obtain neat joins between lengths when hanging.