Hanging Wallpaper: Setting Out and Pattern Repeat

The Ten Minutes That Spend Twelve Rolls

The rolls are stacked in the hall, all one batch, and the merchant has already told you the pattern is a seasonal line with nothing behind it. Nobody is going to make you another two. Every decision that follows — where the plumb line goes, which wall gets hung first, which direction you travel round the room — is made in about ten minutes with a tape, a pencil and a spirit level, and it is made before a single length is cut. After that the room is committed. You cannot slide a papered wall 40 mm sideways because the motif is landing badly on the chimney breast.

What you are actually doing is laying a grid over the room. The paper carries its own two-dimensional grid: 530 mm across, and a repeat distance up the roll that the label states. The room carries a different set of lines — corners, a breast, a door, a window reveal, a picture rail — and none of them are square, plumb or level to each other. Setting out is choosing where to pin the paper's grid to the room's, knowing the two will not agree by the time you get back to where you started.

They cannot agree, and that is the second thing to accept before cutting. Go all the way round a room and the pattern arrives at the closing seam out of step, because the perimeter is almost never a whole number of pattern widths. That mismatch is not a defect and it is not avoidable; it is a fixed quantity of ugliness you get to place. Put it on the wall you look at from the doorway and it is the only thing anyone sees. Put it in the corner the open door stands in front of, and nobody finds it for the life of the paper.

Read the Label Before You Read the Room

Everything the setting out needs is printed on the roll wrapper, and three of the numbers matter more than the pattern name. The width, nominally 530 mm on the European roll that most patterned papers are supplied in, and 10.05 m of length. The repeat, printed in centimetres — the distance up the roll at which the design starts again. And the offset, which only appears when the design is a drop match, telling you how far down the repeat the next drop begins. Alongside them sit the symbols for match type, washability, strippability and light fastness, whose meanings are defined in BS EN 235, Wallcoverings — Vocabulary and symbols, rather than being a house convention that varies between brands. The finished product itself is specified against BS EN 233, Wallcoverings in roll form — Specification for finished wallpapers, wall vinyls and plastics wallcoverings, and the width, length and straightness you are relying on are the properties determined by BS EN 12956, Wallcoverings in roll form — Determination of dimensions, straightness, spongeability and washability.

Match type is the expensive number. A free match paper can be cut to the wall height plus a trimming allowance and nothing else, so the roll gives up almost all of its length as usable drops. A straight or offset match forces every cut to a whole number of repeats, which quantises the cut length upwards and throws away whatever is left of the last repeat on every single drop. On a tall room with a short repeat that penalty is small. On a standard 2.4 m ceiling with a 64 cm repeat it is enough to cost you a roll in four, and the label is where you find that out — not the estimate, and certainly not the wall.

Where the Centre Line Goes

Pick the focal wall before anything else, and pick it standing in the doorway rather than looking at a plan. In most rooms it is the chimney breast; failing that it is the wall the bed or the sofa faces, or simply the wall you see first on entering. That is the surface the pattern has to be deliberate on, and where a half-motif at an arris gets noticed daily for a decade.

Then choose between centring a drop and centring a seam, which sounds like a preference and is arithmetic. The breast face is 1.15 m and the paper is 530 mm. Centre one drop on the face and you get 530 mm in the middle with 310 mm turning each side — two comfortable returns. Centre a seam instead and two full widths take up 1.06 m, leaving 45 mm slivers at each external corner: a sliver on an arris will not stay stuck, it catches every passing sleeve, and it makes the breast look narrower than it is. The general check is to divide the face width by 530 mm and look at what is left over, then shift the whole set sideways by half a width and look again. One of the two options leaves a decent return and the other leaves a sliver; there is no third answer.

Vertical position is the decision people skip, and on a bold pattern it matters as much as the horizontal one. Set the drop so a complete motif sits just under the ceiling line and let the incomplete one fall at the skirting. The ceiling line is a long, uninterrupted horizontal at the top of the room where the eye reads across all four walls at once; the skirting is broken up by furniture, and half a motif behind a sofa is half a motif nobody sees. On papers with a very large single motif, mark the motif's own centre and hold it at eye height on the focal wall instead — around 1.5 m — so the design is looked at rather than looked over.

With the focal wall pinned, work outwards in both directions and let the two runs meet somewhere else. Hanging the breast face first, then its returns and alcoves, then along one long wall and back along the other, brings the two travelling patterns together at one seam. That seam is the mismatch, and now you get to say where it is. The usual home for it is the corner behind the door on its hinge side, where an open door screens it, or the corner above a wardrobe. What it must not be is the wall opposite the door, and it should not be a corner beside a window either — daylight raking along a wall finds every seam, every lifted edge and every pattern break on it, which is exactly why that wall is the last one you want carrying the compromise.

One habit is worth more than any of this: mark it on paper first. An elevation of each wall with the drop lines numbered in hanging order takes fifteen minutes at the kitchen table, settles the argument before the paste is mixed, and doubles as the schedule the order is built from — so the count that goes to the merchant and the count that goes on the wall are the same count.

1. Stand in the doorway and name the focal wall; everything else is set out from it.
2. Measure the developed length of every wall face, including alcove backs and breast returns, not the room's nominal perimeter.
3. Divide the focal face by the paper width and test both centring options — drop on centre, then seam on centre — for whichever leaves the wider return at the corners.
4. Fix the vertical position by holding a complete motif under the ceiling line, and mark that point on the first drop.
5. Draw each wall as an elevation with numbered drop lines, then choose the corner that will take the closing mismatch.
6. Plumb the first line on the focal wall by level, half a paper width either side of the centre you settled on, and only then start cutting.

The Room Is Not Square and the Corners Are Not Plumb

A plumb line belongs on every wall, not just the first, and it is struck before the first drop on that wall rather than inherited from the last one. Corners are rarely plumb; carry a full width round one and the free edge arrives on the new wall leaning, and every subsequent drop on that wall inherits the lean. Even on a straight run the paper's own edge is a poor datum, because a millimetre of error per seam is invisible until nine drops later, when the pattern is a centimetre off vertical against a door casing. Re-check plumb every third or fourth drop and correct at a seam, where a small adjustment disappears, rather than at the end of the wall, where it does not.

Internal corners get cut, never wrapped. Measure from the last seam to the corner at the top, the middle and the bottom, take the largest of the three, add 15 to 25 mm and cut the width to that. The larger piece turns onto the next wall by that small amount and absorbs the corner's error; the offcut is then hung on the new wall against its own fresh plumb line, overlapping the turn. That overlap is the deliberate pattern break, one per corner, and on a room with a chimney breast there are six of them before you have even reached the closing seam. On heavy vinyls an overlap will not hold — vinyl does not stick to vinyl with ordinary paste — so either use the adhesive the maker specifies for a vinyl-to-vinyl lap, or double-cut through both layers on a cutting strip and remove the waste from each side.

External corners are the opposite instruction: wrap them. Take the paper round the arris by about 25 mm and hang the next drop plumb over the return, so no seam falls on the corner itself. A seam on an arris is the first thing to lift and the one thing that cannot be patched invisibly. Ceilings deserve one last look before any of this: run a level along the ceiling line, and if it falls appreciably across a wall, decide which datum wins. Hang plumb and a strong horizontal band in the pattern will taper against the ceiling; follow the ceiling and every vertical element in the design will lean into the corners. On a design with a dominant vertical you hang plumb and let a coving or the trim absorb the taper. On a bold horizontal stripe you may have to split the difference — but you make that call once, before the first drop, and then hold it for the whole room.

Soak Time Is a Dimension

Traditional paste-the-paper wallcoverings expand across their width while they are wet, then contract as they dry. That is not a defect; it is why the maker states a soaking time. What it means for setting out is that the width of a drop is a function of how long it soaked, so if drop one sat folded for eight minutes and drop three went up after three, they are not the same width and they will not dry to the same width. The seams open as they lose moisture, and they open at exactly the point where two different soak times met. Cut the drops in sequence, book them, and put them up in the same sequence with a timer running — the discipline is boring and it is the single most common cause of open seams on an otherwise competent job.

Non-woven paste-the-wall materials behave differently and change the setting out with them. They are dimensionally stable, so there is no soaking, no expansion and no width drift; the paste goes on the wall, the drop goes up dry, and it can be trimmed in place at head and foot. That makes the plumb line more important rather than less, because there is no wet slip to nudge a drop into match — what you hang is where it stays.

Conditions govern all of it. A cold room, a room still drying out after plastering, or a room being force-dried with a fan heater will all produce seams that open and edges that curl, because the adhesive is being asked to grab or release faster than it was designed to. Hang at ordinary room temperature with the heating steady and the draughts shut out, and leave it alone for a day. BS 8000-12 covers the workmanship expectations here, and the adhesive manufacturer's own data sheet covers the rest.

Batches, and What Arrives on the Pallet

Check batch numbers on the tailgate, before a single wrapper is opened. Colour varies measurably between production runs, and two batches on one wall show as a soft vertical band that no amount of lighting fixes and no amount of arguing returns. Every roll for the room comes from one batch, ordered in one go, including the spare — buying the twelfth roll six weeks later against a different run is how a job that went perfectly ends with one visibly different width beside the door. Where a plain or lightly shaded paper is involved, the maker may direct that alternate rolls are hung end for end to average out shading across the wall; on a directional pattern that is not available, which is one more reason the label is read before the order goes in.

Then check the goods themselves. Unroll the first metre of each roll and look down the edge for a shade change, a print fault or a trim that wanders — the dimensional and straightness properties determined under BS EN 12956 are exactly what you are eyeballing, and the moment to raise a fault is while it is still the supplier's problem. Keep a labelled offcut of at least one full repeat, with the batch number written on the back, taped inside a cupboard when the job is done. A future repair cut from that offcut is invisible; the same repair ordered five years on against a reprint is a patch everybody can find.

Choosing a Paper the Room Can Live With

Setting out assumes the paper belongs there in the first place, and durability is a specification rather than a taste. ASTM F793, Standard Classification of Wall Covering by Use Characteristics, sorts wallcoverings into classes by the service they are built for, which is the honest way to answer whether a delicate print belongs in a hallway with a dog and a pushchair. Washability and abrasion symbols on the European label, defined under BS EN 235, carry the same message in a different notation. A paper that has to come off in three years because it was hung at knuckle height in a circulation route was the wrong purchase however well it was set out.

In anything other than a private dwelling, the reaction-to-fire performance of the wallcovering is a regulated property, not a preference. Under the International Building Code, Chapter 8, Interior Finishes, as adopted and amended locally, interior wall and ceiling finishes are classified from testing to ASTM E84, Standard Test Method for Surface Burning Characteristics of Building Materials, with the permitted class depending on the occupancy and on whether the space is an exit enclosure, a corridor or a room. In Europe the equivalent classification comes from EN 13501-1, Fire classification of construction products and building elements — Part 1: Classification using data from reaction to fire tests. Corridors and stairs are where the requirement bites hardest, and a decorative paper chosen from a sample book will usually not carry the class those spaces need.

One last property decides where an impermeable wallcovering can safely go. A solid vinyl is close to a vapour retarder in its own right, with a permeance measured by ASTM E96/E96M, Standard Test Methods for Water Vapor Transmission of Materials. Applied to the inside face of an air-conditioned building in a hot, humid climate, it sits on the cool side of a wall that vapour is being driven into from outside, and moisture accumulates behind it — a well-documented failure mode addressed in the ASHRAE Handbook—Fundamentals chapters on heat, air and moisture control in building assemblies. That is a decision for whoever owns the wall assembly, not one to take alone on site with a sample book.