How do you clean a mattress and get rid of dust mites?

It is the most widely shared piece of advice about mattresses, and the one that causes the most silent damage.

The usual protocol — cover the sleeping face with bicarbonate, leave it overnight, vacuum — rests on a false assumption: that the powder stays on the surface. It does not. Bicarbonate is a fine crystal, and a mattress is an open structure: quilted seams, tufting, anchor points, foam cells. The powder goes down.

What a domestic vacuum then recovers is the top layer. The rest is trapped a few millimetres below the sleeping face, where it waits for the next dose of moisture — one night's perspiration is enough.

On contact with water it forms an alkaline paste that stiffens the fibre of the ticking, impedes evaporation and holds dust. Repeated every month for two years, the result is a mattress that is rougher and slower to dry than it started.

The defensible use of bicarbonate comes down to three conditions: a thin layer, less than an hour, over a limited area, with slow, crossed vacuuming afterwards. As an emergency absorbent on a freshly spilled liquid, it earns its place. As a monthly ritual across the whole surface, it does the opposite of what is expected of it.

The internal structure determines what a mattress does with the water it receives. It is the parameter nobody looks at before wetting one.

The pocket-sprung mattress. Below the comfort layer there is void and metal. Water that travels down that far meets nothing to hold it, but nothing to bring it back up either: it stagnates at the bottom of the carcass, out of reach of any extraction, and takes days to evaporate. The associated risk is twofold: a persistent smell and, beyond that, oxidation on untreated springs.

Memory foam. This is the most delicate case. Viscoelastic foam has mostly closed cells: it absorbs slowly and gives back even more slowly. Excess water stays trapped in it, exactly as in a sponge nobody wrings out. It is the substrate on which over-wetting produces the most stubborn smells.

Latex. Dense, heavy, barely permeable at the surface. It tolerates soaking badly and strong alkalis very badly indeed, since they attack the material itself.

The practical conclusion, valid for all three: on a mattress, the quantity of water is the main risk variable. Little solution, a great deal of extraction — the exact opposite of the logic that governs a rug, and the reason bedding follows a protocol of its own.

A child wetting the bed, a spilled glass of water, a nosebleed: what you do straight away counts for more than what you do the next day.

1. Absorb, do not rub. White absorbent paper or a white towel, pressed flat, changed as soon as it is saturated. Rubbing drives the liquid in and breaks up the structure of the ticking.
2. Press with your body weight. The liquid rises by capillary action towards the paper for as long as the pressure is maintained. Twenty seconds of firm pressure are worth five minutes of limp dabbing.
3. Cold water only. Urine, blood, milk and vomit are protein stains: heat coagulates the protein and fixes it permanently in the fibre. It is the most frequent mistake and the only completely irreversible one.
4. No bleach, no perfumed detergent, no stacking of products. A product applied on top of another one's residue creates an unpredictable reaction and leaves a ring.
5. Dry it immediately: mattress stood on its edge so both faces can air, window open, fan on. A closed bedroom is the worst possible place.

The main enemy is not the stain, it is the time the stain spends damp and shut in.

The scenario is always the same. The area was cleaned, it looked spotless once dry, and a few days later a yellow outline reappears, often wider than the original stain.

The explanation is physical. A urine or perspiration stain is made of two things: a soluble fraction, which water removes easily, and crystallised salts and pigments, which stay deep down.

Every rise in moisture — a night's perspiration, a change of season, an unfinished drying — redissolves them, moves them towards the surface and redeposits them at the edge of the evaporation zone. The ring therefore reforms on its own, indefinitely, for as long as the crystals are there.

Rinsing more makes it worse: you add water, you redissolve, you redeposit further out. The only way out is an enzyme treatment that breaks down the organic matter, followed by an extraction that removes it from the mattress. Without those two steps, you are repainting a symptom.

It is also why a urine smell always returns on the first hot day: the odour molecule is carried by those same crystals. The full logic, stain family by stain family, is set out in our analysis of stains and their chemistry.

Useful bedding care comes down to four actions, and none of them costs money.

• Air the bedroom every morning, sheets turned back, for twenty to thirty minutes before making the bed. A bed made immediately shuts the night's moisture into the comfort layer. It is the most profitable action on this list.
• Turn the mattress head to foot, and turn it over face for face if it is double-sided, at the change of season. That spreads the compression and, above all, exposes the other side to the air.
• Vacuum the sleeping face once a month, slowly, working into the seams and the tufting where the deposit accumulates. A slow, crossed pass: a vacuum run quickly only strokes the surface.
• Change the waterproof protector and the mattress pad often. Those are the two items designed to take what the mattress must not receive, and they only do that job if they are renewed before they are saturated.

What this calendar does not do: remove what has already penetrated. Bedding cared for from day one ages very well; seven-year-old bedding that has never been treated carries a backlog that vacuuming will not make up.

The house dust mite does not eat dust: it eats skin flakes. A mattress offers it the three conditions it needs — food, warmth, moisture — and that is what makes it the main concentration zone in a home, well ahead of a rug or a curtain.

Three practical consequences, often counter-intuitive:

• Moisture is the most effective lever. A dust mite copes badly with dry air. Airing the bedroom and bringing the room's humidity down works more reliably than any spray.
• What triggers the allergy is not the living mite, but its droppings and debris, which stay in the mattress after it dies. Killing without removing therefore solves nothing for an allergic person: it has to be extracted.
• An anti-mite cover is a barrier, not a treatment. It separates the sleeper from the existing population; it does not make that population disappear.

That is why, for an allergic person, what matters is removing the debris and droppings where the mite concentrates: the mattress and children's bedding first, well ahead of a lightly used rug. An extraction brings out what vacuuming leaves behind; a single mattress is 300 MAD incl. VAT and a double 400 MAD incl. VAT, as set out in the soft furnishings price grid.

This has to be said before anything is invoiced.

Not recoverable: deformation of the filling — a hollow, a dip, one side sagging — which is mechanical wear, not soiling; mould established deep down after water damage, where the growth has reached the core; a burn or bleach discolouration, where the fibre itself has been altered; torn ticking.

Still recoverable: almost all old organic stains, on a best-efforts basis and with the result stated before the intervention; smells whose source is matter held in the comfort layer; the diffuse soiling that yellows the sleeping face.

The decision criterion is simple: if the structure is sound, a treatment is worth the money; if it is not, no cleaning will make a mattress comfortable again. We establish that on arrival and say so before starting, in the same way as what the process can and cannot do.

Grouping the household's mattresses into the same visit avoids paying a top-up: a single mattress on its own is brought up to the 400 MAD textile minimum, whereas a single and a double come to 300 + 400 = 700 MAD incl. VAT, with no top-up.

Allow half a day to a full day of drying before making the bed, and note that no 100% result is guaranteed on an old ring. The price is confirmed from photos through the quotation form.