How do you protect patio doors from sand and wind in Marrakech?

This is the distinction that governs everything else. Dust in a European flat is organic and light: textile, skin, pollen, soot. It wipes off.

What the chergui brings is mineral. This hot, dry wind blowing up from the east in late spring and summer carries fine sand — mostly quartz and limestone dust torn from the plain. Two properties follow from that, and both are unpleasant:

• Hardness. Quartz is harder than glass. A grain caught in a cloth or under a squeegee blade does not deform: it scratches. That is why glazing in Marrakech is never, ever wiped dry.
• Fineness. The finest fraction stays airborne for several hours after the gust and settles slowly, including indoors, including with windows closed, through the seals and drainage holes of the frame.

Add the relative humidity of the nights: the dry deposit reforms into a film that clings to the glass. Three months later, it is no longer a deposit to rinse off but a film to be lifted. The mechanism of the mark itself is explained in our guide to cleaning windows without leaving streaks.

On the same villa, two identical patio doors do not have the same needs. The gap comes from three compounding factors, and it runs at roughly three to one between the best and the worst exposure.

• Orientation relative to the prevailing wind. The chergui comes from the east. East and south-east façades receive the load first and in the greatest quantity.
• Radiant heat. A due-south door reaches a high surface temperature by mid-morning. Any droplet that lands on it — loaded rain, a sprinkler splash, washing water — dries instantly and bakes its mineral content onto the glass. That is the difference between a deposit that sits and a deposit that fixes.
• Run-off. A south façade in Marrakech gets little washing rain, and what it does get is loaded with atmospheric dust. It never rinses itself.

Direct budget consequence: a villa should not be treated uniformly. A serious maintenance schedule treats south- and east-facing doors at every visit, and north-facing ones every other visit. Because each patio door is priced as a unit, a visit limited to the exposed doors costs less than a complete one: the schedule lowers the bill rather than inflating it.

This is the point nobody connects, and yet it is the leading cause of permanently marked glazing in the villas of Targa, the Palmeraie or the Ourika road.

The mechanism runs as follows. A lawn sprinkler or a border drip line sprays fine droplets of mains or borehole water onto the base of patio doors several times a week. This water is hard. It dries within minutes on sun-exposed glass, leaving a mineral ring. The operation repeats hundreds of times a season.

Three stages follow one another:

1. The film. In the first months, the deposit stays on the surface and comes off with a plain-water wash.
2. The crust. After a season, the layers build up and need a specific, longer, sometimes mechanical treatment.
3. The etching. After years, the limescale has attacked the silica at the surface. The deposit is no longer on the glass, it is in the glass. No wash removes it, and we say so from the photos rather than charging for a pointless treatment.

The useful corrections cost nothing: adjust sprinkler heads so none hits a façade, water early in the morning rather than in full sun, and move border drip lines away from doors they are pressed against. Glazing that receives water which then dries on it is glazing condemned in the medium term.

The question "how often" has no general answer, only a seasonal one. Here is the one we apply in Marrakech.

• February–March. End of winter. The glazing carries the deposit of loaded rain and westerly winds. This is the best moment for a complete pass, north faces included: the result will hold until the chergui picks up.
• May–June. Entry into the windy season. This is the most useful pass of the year: it removes the accumulated load before it bakes on under summer temperatures. Glazing treated in May comes through the summer properly; glazing left as it is will need deep retreatment.
• July–August. Peak deposit period. On an open villa, a commercial unit or a showroom, an intermediate pass on the exposed doors only is often more cost-effective than a complete pass.
• September–October. End of the windy season. A complete pass, the one that resets the building before winter.

Translated into a rhythm: four passes a year on exposed faces, two on sheltered ones. Below two annual passes, the glazing sooner or later tips into the surcharges — +20% for very dirty glass, +40% for encrusted limescale — and the apparent saving shrinks. The twelve-month cost reasoning is developed in our article on window prices.

Between two interventions, a few habits genuinely change the condition of a patio door.

1. Vacuum the track dry, every week, with a flat crevice tool. This is the most cost-effective step on the list. Sand accumulating in the runner rides up onto the glass every time the panel is moved, and wears the roller. Counting and treating the track is detailed on the patio doors page.
2. Clear the drainage holes at the bottom of the frame with a stiff wire. Blocked by sand, they hold rainwater that then overflows inside the profile and runs down the glass, carrying frame dust with it.
3. Rinse thoroughly with clean water after a windy spell, without rubbing. This isn't cleaning, it's flushing the mineral load out before it bonds.
4. Close shutters or brise-soleil during gusts, where the building has them. It doesn't protect fully, but it halves the load reaching the glass and the track.

The one thing never to do: wipe a dusty door dry, with a cloth, paper or a duster. You are dragging an abrasive across a soft surface. The micro-scratches obtained do not fade, they accumulate, and glazing maintained this way for two years takes on a permanent dull look in raking light.

Take a concrete case and work it through in full, the way a client should be able to.

A villa has 10 patio doors of up to 4 m² and 12 windows of up to 2 m². A patio door is counted whole, not by the panel: 10 × 150 = 1,500 MAD for the doors and 12 × 75 = 900 MAD for the windows, giving 2,400 MAD incl. VAT per complete pass, frames, tracks and reachable roller shutters included. The 400 MAD minimum call-out charge does not come into play.

Two scenarios over the year:

• Four passes, two complete and two limited to the six south- and east-facing doors. An intermediate pass comes to 6 × 150 = 900 MAD. The year therefore costs 2 × 2,400 + 2 × 900 = 6,600 MAD, and the glazing stays at the base price every time.
• A single pass a year. The glazing will have accumulated a whole windy season and a whole watering season. If the glass is very dirty, +20% is added to the base: 2,880 MAD. If limescale is encrusted, +40%: 3,360 MAD, with a caveat — depending on the surface, some marks may remain.

The honest calculation is this: the rhythm costs more over the year, the single pass costs more per pass, and it gives limescale time to reach the etching stage, which no wash can reverse.

If you choose a rhythm, start in February rather than August: the month of the first intervention determines the rest of the calendar. An estimate can be requested here, with no commitment, and the price is confirmed after photos or a visit. The full technical context is on window cleaning in Marrakech.