Storing a rug without damaging it

Roll, never fold

A hand-knotted rug is a structure under tension: taut warp threads, weft threads passed between them, knots tied tight around both. To fold it is to crush that structure along a line and hold it there. The cotton fibres break one by one, always in the same place, and the fold line becomes a permanent weakness.

The result shows after a few months: a pale mark that no longer comes out, the pile opening in a V along the fold, then a clean split the day it is unrolled a little too quickly. On an antique rug, a few weeks folded under a stack of boxes are enough. A split of this kind can be repaired — that is reweaving — but it is repaired in the workshop.

Rolled, the rug spreads the strain over the whole length of the roll and no point works harder than another. It is the only correct way to move it and to store it, including for two days of building work.

Which way round, and on what

Run your flat hand over the pile, one way and then the other. One way it is smooth and the colour lightens; the other it catches and the colour darkens. The smooth direction is the direction of the pile. Start the roll at the end towards which the pile lies: the pile then rolls up with its own direction, lying down instead of being pushed back the wrong way along the whole length.

Back on the outside. It is the face that has nothing to fear and it is the one that should take the rubbing of the floor, of the cover and of the transport; the pile ends up protected on the inside. On a long pile, roll wide: the larger the diameter of the roll, the less the pile is compressed at the core.

On a tube, always. A rug rolled on itself ends up marked at the centre, where the radius is smallest. Take a rigid tube at least ten to twelve centimetres in diameter, more for an antique piece, and longer than the width of the rug by about ten centimetres at each end: it is the ends of the roll that get crushed in handling. A bare cardboard tube is acidic; wrap it in washed cotton cloth before rolling.

The roll is stored flat, on a shelf or on two supports, never upright. Upright, the whole weight rests on a few centimetres of border and the roll settles from the bottom within a few months. And nothing is ever put on top of it: a roll is not a shelf.

What to put round it, and what never to

No airtight plastic. Wool is hygroscopic: it exchanges moisture with the air constantly and always holds some. Shut inside an impermeable film, that moisture can no longer get out, and it takes only a difference in temperature between day and night for it to condense against the film, and so against the rug. Three summer months in a garage are enough to produce a musty smell, brown tidemarks and sometimes moulds that stain pale wools for good.

Wrap in cloth: a washed cotton sheet, an undyed canvas, or a breathable technical fabric. The job of the wrapping is to stop dust and light, not air.

One qualification, because it matters and because it looks contradictory: a genuinely closed wrapping does make sense against moths, and that is what we do after a wash and a treatment. But the rug in that case is perfectly dry, out of a complete and controlled drying, and stored in a room whose temperature is stable. That has nothing to do with a removal film wound round a rug that is still damp and laid on a cold slab.

Neither the cellar nor the loft

The cellar combines everything that damages a textile: high and constant relative humidity, a cold floor on which the ambient air condenses, rising damp in the walls, complete darkness and no air movement. A rug picks up the smell there in a few weeks and mould in a few months. The smell of a cellar on wool is not a surface smell: it is in the fibre, and it takes a full wash to get it out, when that is still possible.

An uninsulated loft poses the opposite problem and is just as bad. Under an exposed roof, the temperature climbs very high during a summer day and falls back at night, and the relative humidity follows those swings in the opposite direction: the wool swells and contracts to the rhythm of those cycles, day after day. Add what lives in a loft — birds' nests, the bodies of small animals, droppings — that is, permanent moth infestations a few metres from a rolled rug, motionless and in the dark.

Store inside the heated volume, or in a room whose behaviour you know: a spare bedroom, a dressing room, the top of a wardrobe, a temperature-controlled storage unit. The criterion is not comfort, it is stability.

Humidity, the one figure to watch

A hygrometer costs little and replaces every intuition. Aim for a relative humidity between 45 and 55%, at a moderate and above all stable temperature. Wool in everyday use tolerates a wider range, 40 to 60%; the band is narrowed to 45-55% for conservation, because in long storage it is stability that counts for more than the exact figure. These are the values used in textile conservation, and they hold without any particular equipment in a normal living room.

Two limits really count. Above a sustained 65 to 70% relative humidity, mould growth becomes possible, and it is irreversible on a pale wool. Below 35%, the wool loses its suppleness and the cotton foundation turns brittle. Between the two, the exact value matters less than its stability: it is rapid, repeated variation that tires the fibre.

Add darkness, which costs nothing. Light fades colour, and it does not fade every colour at the same rate: a rug stored near a window comes out with a pale band and an unbalanced design, which is far harder to put right than uniform fading.

Before rolling: wash, dry, check

A rug is stored clean, and that is not a matter of tidiness. Moth larvae attack the keratin of the wool, but they also attack fibres soiled with animal matter — perspiration, urine, food greases. A rug stored dirty is a larder, left for two years in darkness and stillness, that is, in exactly the conditions the moth is looking for. That is the direct link between washing and storage.

• Vacuum both faces, borders and fringes included, then the floor under the rug
• Wash by hand and with water: washing flushes out the eggs, the larvae and the frass
• Dry completely, right through the foundation, and check the back by hand
• Treat by cold or by anoxia at the least doubt, before wrapping and not after
• Roll in the direction of the pile, back outwards, on a tube longer than the width
• Wrap in cloth, store flat, and put a pheromone trap in the room

A rug that seems dry at the surface may not be dry in the foundation, and that is the most frequent mistake as well as the most expensive: two days of insufficient drying, two years of closed roll, and you find a brown tidemark that has migrated through to the front. In the workshop, flat drying takes under twenty-four hours because it is carried out in controlled conditions; at home, allow longer and roll only after running your hand over the back without feeling the least coolness.

Bringing it back out after two years

Do not unroll it in one go. Lay the roll on the floor on a clean surface and unroll slowly, guiding it: a rug long rolled has taken the shape of the tube and its foundation must be brought back flat without being forced. Then leave it lying flat for twenty-four to forty-eight hours before putting furniture back on it. Ripples at the edges usually settle by themselves within that time; those still there after a week will not go on their own.

Check it before putting it back into service, and start with the back, which tells you everything: cocoons stuck along the borders, granules of frass at the base of the pile, cream-white larvae in the folds, cast skins, grazed patches. Look particularly at the two ends of the roll, which are the most exposed. And smell it: a cellar smell means the rug has taken up moisture, and that is settled by a wash, not by airing.

Then vacuum both faces, slowly. If you find cocoons or granules, stop there and treat before laying the rug down again — see the guide to carpet moths. If the back is stiff, if brown marks have migrated through to the front, or if the rug refuses to lie flat after a week, it is a problem of prolonged damp: it is dealt with in the workshop.