# Glass curtains by the sea: wind, salt and maintenance

> What changes for glass curtains on the seafront: wind pressure, salt in the tracks, the aluminium finish and the care routine that keeps them running.

## Can you fit glass curtains on a seafront terrace?

Yes, glass curtains work on the seafront, but the sea asks more of them. Spain's building code gives the shoreline a wind exposure factor almost double the town figure at low heights, and salt attacks tracks and fixings. Ask for a coastal grade coating, A4 stainless screws and a fresh water rinse every few months.

Being on the coast does not rule them out, but it changes two things: how hard the wind pushes and how quickly the metal parts get dirty and corrode. An enclosure that needs almost no attention in an inland courtyard will want more frequent checks, and materials chosen with salt in mind, on a balcony facing the beach or a penthouse above the promenade. That applies right across our [working area from Valencia to Murcia](https://luneks.es/en/areas/).

By the sea the small parts wear first: rollers, bearings, seals and screws. Toughened glass and well protected aluminium cope with salty air for years, but salt mixed with sand turns the bottom track into fine sandpaper. That is why seaside care is mostly about the tracks and rinsing with fresh water, rather than about the glass itself. (to be confirmed)

## How much harder does the wind push on the coast?

The [SE-AE section of the Spanish building code](https://www.codigotecnico.org/pdf/Documentos/SE/DBSE-AE.pdf) sets the basic dynamic wind pressure at 0.42, 0.45 and 0.52 kN/m² for zones A, B and C of the national map. Alicante sits in zone B, according to the [Normatia technical sheet for Alicante](https://normatia.com/es/municipios/comunidad-valenciana/alicante-alacant/alacant-alicante/). That pressure is then multiplied by an exposure factor that depends on height and surroundings, and the harshest surroundings in the whole table are the seashore.

Table 3.4 of the same document gives a seashore with at least five kilometres of open water in front of it a factor of 2.7 at six metres up, against 1.4 in a built-up urban area. At 15 metres, roughly a fifth floor, the figures are 3.3 against 2.1. Put simply, the same panel facing the beach takes between 42 and 93 % more pressure than one further into town, and the system has to be sized for that.

## What should you ask for in seafront glass curtains?

First and foremost, the system should be designed for the real wind on that particular façade, not an average figure. Glass thickness, the spacing of the fixings and the type of track all depend on height and on how exposed the terrace is. [Glass curtains](https://luneks.es/en/glass-curtains/) for a ground floor flat with a garden and for a penthouse 20 metres above the promenade should not share the same specification.

In a strong easterly or a storm, the panels should be fully closed and locked, or completely stacked away. A panel left half open acts like a sail and strains the hinges and the track. Ask the fitter to show you the lock on day one, and use it whenever you leave home with wind in the forecast. (to be confirmed)

- A wind load calculation for the height and orientation of the façade
- Toughened glass of the thickness that calculation calls for
- An aluminium coating rated for marine conditions
- Screws and anchors in A4 (AISI 316) stainless steel
- A bottom track with drainage, so salt does not settle in the channel

## How does salt affect the aluminium and the fixings?

Sea air carries chlorides that settle on the profiles and, together with overnight damp, attack any unprotected spot in the metal: cut ends, drill holes, scratches in the coating. That is why the Qualicoat association created its Seaside class for projects within five kilometres of the coast, which requires etching away at least 2 g/m² of aluminium before coating instead of 1, as [Glass Times reports on the Seaside class](https://glasstimes.co.uk/news/garnalex-gains-qualicoat-seaside-class-licence/).

For fixings, molybdenum makes the difference. Type 316 stainless steel, marked A4 on screws, resists localised chloride attack better than type 304 or A2, as the [Wikipedia article on 316L stainless steel](https://en.wikipedia.org/wiki/SAE_316L_stainless_steel) notes. On the seafront a lower grade screw eventually shows rust spots, and the brown streaks stain both the coating and the glass. If you would like the aluminium in another colour, our [RAL coating](https://luneks.es/en/ral-coating/) page sets out the options.

## How often should seafront glass curtains be cleaned?

More often than inland. The aluminium systems maker Reynaers recommends using its care product on profiles and glass twice a year in rural settings and four times a year in aggressive environments such as the coast, as [Interempresas reported when its care manual came out](https://www.interempresas.net/Cerramientos_y_ventanas/312171-Reynaers-Aluminium-lanza-su-nuevo-manual-de-uso-cuidado-y-mantenimiento.html). As a working rule on the seafront, rinse the curtains with fresh water every three months and again after every storm.

The weak spot is the bottom track. Sand, salt and rainwater collect there, and that mixture wears down rollers and brush seals until the panels start to drag. Vacuuming the track before you wet it stops the sand acting like sandpaper. Worn parts can be replaced without taking the glass out, as we explain on our [seals and spare parts](https://luneks.es/en/seals-and-spare-parts/) page.

## Do the seals stand up to coastal sun and damp?

Glass curtain seals are usually made of EPDM rubber or similar elastomers. EPDM is known for its resistance to heat, ozone and weathering, and when properly formulated it can be used outdoors for years or even decades without breaking down, as the [Wikipedia article on EPDM rubber](https://en.wikipedia.org/wiki/EPDM_rubber) explains. That matters in a city that, according to [AEMET](https://www.aemet.es/es/serviciosclimaticos/datosclimatologicos/valoresclimatologicos?l=8025&k=val), gets around 2,851 hours of sunshine a year. (to be confirmed)

What shortens their life on the beach is not the sun but friction. Sand stuck to the rubber by the salt acts as an abrasive every time the panel slides, and the seal loses its shape early. Wiping the seals with a damp cloth when you rinse the track, and never forcing a panel that drags, stretches the time between replacements considerably.

## How different is wind exposure on the beach and in town?

Exposure factor from table 3.4 of the [SE-AE section](https://www.codigotecnico.org/pdf/Documentos/SE/DBSE-AE.pdf). It multiplies the basic wind pressure, which in Alicante, zone B, is 0.45 kN/m². Floors are approximate, at about three metres per storey.

| Height | Seashore (type I) | Urban area (type IV) | Difference |
| --- | --- | --- | --- |
| 3 m, ground floor | 2.4 | 1.3 | +85 % |
| 6 m, second floor | 2.7 | 1.4 | +93 % |
| 15 m, fifth floor | 3.3 | 2.1 | +57 % |
| 30 m, tenth floor | 3.7 | 2.6 | +42 % |

## How do you look after seafront glass curtains step by step?

1. **Vacuum the track.** Before wetting anything, lift the sand out of the bottom track with a narrow nozzle, so you do not drag it along the channel.
2. **Rinse with fresh water.** Run plain water over profiles, tracks and screws to dissolve the salt. A gentle hose is enough, with no pressure jet aimed at the seals.
3. **Wash the glass.** Water with a little neutral soap, a soft cloth and a rubber squeegee, early in the morning or at dusk, out of direct sun.
4. **Dry the metal.** A dry cloth over profiles and screw heads stops salty droplets drying on them.
5. **Check seals and rollers.** Slide each panel and listen: squeaks or jerks mean worn bearings or seals.
6. **Book a service.** Once a year, have a fitter adjust the system and replace worn parts. (to be confirmed)

> On the seafront it is not the glass I see failing, it is the rollers. Sand gets into the track, salt cakes it together and the panel starts to stick. A handheld vacuum and a bucket of fresh water every few months do more for a curtain than any expensive product.
>
> Mikhail, founder of LUNEKS

## What else do people ask about glass curtains by the sea?

### Can glass curtains stand up to the wind on a seafront penthouse?

They can, provided the system is designed for that specific façade. The Spanish building code gives the seashore far higher exposure factors than town, so height and orientation change the glass thickness and the fixings needed. (to be confirmed)

### What should I do with the curtains in a storm?

Close and lock them fully, or stack them away if the manufacturer recommends it. The risky thing is leaving panels half open, because the wind pushes on them like a sail and strains hinges and tracks. After the storm, rinse everything with fresh water to wash off the salt it leaves behind.

### Does sea salt damage the glass?

Toughened glass does not corrode in salt, but dried deposits leave a whitish film, and if you rub them off dry the sand they carry can scratch the surface. The metal is what really suffers: tracks, rollers and screws. So rinse generously with water first, then clean with a soft cloth.

### Which aluminium coating is best near the sea?

For projects within five kilometres of the coast there is the Qualicoat Seaside class, which calls for a deeper etch of the aluminium before coating so the finish grips better and resists the corrosion that creeps underneath. Always ask whether the profiles were coated to that class. (to be confirmed)

### How often do seals and rollers need replacing by the sea?

There is no fixed interval, because it depends on exposure and how often the panels are moved. The signs are clear: panels that squeak or stick, draughts or water between panels, and seals that have hardened or cracked. On the coast, have them checked every year. (to be confirmed)

### Can I use a pressure washer to remove the salt?

Best not to aim it at seals and brushes: a pressure jet can force water and sand into the roller bearings and lift the seals out of their channel. To shift the salt, a hose on a gentle setting or a bucket of fresh water and a sponge is enough, followed by a dry cloth on the metal.

## What should you read after this seaside guide?

- [How to clean and look after glass curtains](https://luneks.es/en/blog/clean-maintain-glass-curtains/): The full routine for the glass, the tracks and the seals, and what never to use on them.
- [Glass curtains or insulated curtains: which keeps the heat in](https://luneks.es/en/blog/glass-curtains-vs-insulated/): How much heat single glass loses compared with double glazing, and when the upgrade pays off.
- [Glass curtains for expats on the Costa Blanca](https://luneks.es/en/blog/glass-curtains-for-expats/): What to know before enclosing your terrace if you live on the coast as a foreign resident.

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https://luneks.es/en/blog/glass-curtains-by-the-sea/