Sea Air and Exterior Paint: How to Protect Your Home

Near the sea, the sea air carries salt that builds up on walls and metalwork. To protect the house, wash off the salt with fresh water before painting, repair cracks, use paints suited to coastal environments and repeat the cleaning every year. The paint lasts longer when the preparation is done well.

What sea air does to a house

The air near the sea carries tiny droplets of salt water. When they dry, salt is left on walls, glass, railings and gates. Salt attracts moisture and speeds up rust on metal. On walls, blisters can appear in the paint, along with whitish stains.

This applies to many houses along the Cascais line and on the coast of Sintra and Oeiras, especially those most exposed to the sea wind. The closer to the coast and the less sheltered, the greater the effect.

Preparing the surface properly

If you paint over salt, the paint does not bond well. That is why preparation matters more than it does for houses far from the coast.

  1. Wash the wall with fresh water, without strong soap, to remove the built-up salt.
  2. Kill algae and mould with a suitable product and rinse.
  3. Scrape off loose paint and repair cracks with exterior filler.
  4. Let the wall dry well.
  5. Apply the primer recommended for the surface and only then the topcoat.

Choosing the right paint

Look for exterior paints with good resistance to water, UV, algae and mould. Some manufacturers state on the label when a product is suitable for coastal environments. Read the instructions and ask for advice in the shop, saying how far the house is from the sea.

A paint with a flexible film helps it follow the small cracks that sun and damp open up over time. A paint that forms a film that is too hard may crack more easily.

Watch the metal

Metal is the weakest point. Gates, railings, handrails, window frames and light fittings rust faster with salt. If you see rust, deal with it straight away: sand it, remove the dust, apply an anti-corrosion primer and finish with exterior enamel.

Maintenance through the year

A gentle wash with fresh water every year, preferably at the end of summer or in spring, removes the salt and dirt. This helps the paint last longer. Pay attention to the eaves, shutter boxes and areas where water runs and collects.

Do not wait until the paint is falling off before acting. Touching up a small flaw costs far less than redoing an entire wall.

Safety

On multi-storey houses near the sea, the wind is usually stronger. Do not work at height without equipment. For high areas, hire professionals with scaffolding or a platform.

Tip: Paint on dry days with little wind. With a sea breeze, fresh paint can end up with salt and dust stuck to it before it dries.

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