Damp stains on walls and ceilings: where they come from

Painting over it does not work

It is the most common temptation: a coat of paint and that is that. But if the damp keeps getting in, the stain reappears, the paint lifts and mould can grow. First the source has to be identified, and then the treatment decided.

1. Penetrating damp: water gets in from outside

This is damp that comes from a terrace, a flat roof, a facade or a badly sealed window.

• The stains appear or grow after rain.
• They are usually on ceilings below terraces or on outside walls.
• They can leave yellowish or brown tide marks.

The solution is to stop the water getting in, often by waterproofing the terrace or treating the facade properly, and then to make good and paint the inside.

2. Condensation: the damp is inside the home

Water vapour from showers, cooking and breathing condenses on the coldest parts of the home.

• It appears in corners, behind furniture, on bathroom ceilings and around windows.
• It usually comes with little black spots of mould.
• It gets worse in winter and in poorly ventilated rooms.

Here paint does help: the mould is cleaned off and disinfected, and the area is painted with a paint designed for damp areas. It is also worth improving the ventilation.

3. Rising damp: the damp comes up from the ground

Water from the ground rises up the walls as if through a sponge.

• It affects the lower part of the walls, in a more or less even band.
• The paint lifts and white salts appear.
• It is more typical of ground floors and old houses.

Rising damp is not solved with paint: it needs a specific damp treatment. We are painters and do not do building work, so if we detect rising damp we will tell you plainly before quoting for anything.

What if it is a pipe?

If the stain appears suddenly, does not depend on the rain and is near a bathroom, a kitchen or a downpipe, it may be a water leak. In that case, a plumber has to repair it first. Then the area is made good and painted.

How to prevent condensation

• Air the home every day, especially bedrooms in the morning and the bathroom after a shower.
• Use the extractor fan in the kitchen and the bathroom.
• Avoid drying clothes indoors whenever you can.
• Move furniture slightly away from outside walls so air can circulate.
• Keep the temperature as steady as possible in winter.

What to do in the meantime

Until the damp is treated, it is best not to cover the stain with furniture or pictures, to air the area and not to paint over it. If there is mould, better not to scrape it off dry, so as not to spread it. Take photos of the stain on different days: they will help us work out whether it changes with the rain or with how the home is used.

Damp in coastal homes

In Águilas and all along the coast, humidity is high for a good part of the year. Homes that are closed up for long spells, like many second homes, are especially prone to condensation and mould. Airing the home when you arrive and before you lock up, and painting bathrooms and kitchens with paint for damp areas, helps a great deal.

How we look at it

During the free visit we look at where the stain is, what it is like and when it appears. If it can be solved with paint or with waterproofing, we give you the quote in writing. If it is not a painting job, we tell you so you do not waste your money.

Frequently asked questions