Damp and mould are common issues in many Portuguese homes, especially during autumn and winter. This is due to several factors: older construction, poor ventilation, water infiltration, and the humid climate — particularly in coastal and mountainous areas.
Whether you're a landlord or a tenant, it’s worth knowing how to prevent and fix these problems before they cause more serious damage to the property or to your health.
Quick Checklist: What to Do About Damp and Mould
- Ventilate the home daily
- Use a dehumidifier during the most humid months
- Avoid drying clothes indoors
- Keep furniture away from the walls
- Check for leaks and insulation issues
- Clean mould as soon as it appears
- Apply anti-mould paint in problem areas
- Explain good practices to tenants
1. Daily Ventilation: Simple and Essential
Many Portuguese homes have poor natural ventilation, which leads to stagnant, humid air. To tackle this:
- Open the windows every day, even in winter, for at least 15 to 30 minutes
- Prioritise opposite windows to create a draft
- Use extractor fans in the kitchen and bathroom, if available
- Don’t block air vents or the small “holes” near windows — they help air to circulate
2. Use a Dehumidifier
This is one of the most effective ways to reduce moisture. Electric models can remove litres of water from the air each day. They’re especially useful:
- In north-facing rooms (which get less sun)
- In areas with little ventilation
- In homes with cold walls.
Even the smaller, more affordable dehumidifiers can make a difference.
3. Avoid Drying Clothes Indoors
We know it’s hard to dry clothes outdoors in winter — but drying them inside significantly increases humidity levels, which encourages mould growth.
If drying indoors is unavoidable:
- Dry clothes near an open window
- Use a dehumidifier in the room
- Never dry clothes in the bedroom where you sleep.
4. Keep Furniture Away from the Walls
Avoid placing beds, sofas, wardrobes, and bookcases directly against the walls — especially in north-facing rooms or those with signs of damp. Leave at least 5 cm of space to allow air to circulate.
5. Watch Out for Leaks and Insulation Problems
Sometimes the problem comes from the outside: rain entering through cracks, leaking pipes, or poorly sealed windows. Do a regular check:
- Stains on ceilings or walls?
- Plaster falling off?
- Water pooling around the windows?
If you notice anything, it’s best to deal with it quickly. You may need to seal windows, apply waterproof coatings, or call a professional.
6. Clean Mould Quickly
Whenever you see black or greenish spots, clean them immediately to stop them spreading. You can use:
- Pure white vinegar: spray it on, leave it for an hour, then wipe off
- Commercial anti-mould products: available in supermarkets and hardware shops
- Bleach (with care): effective, but only use with windows open and wearing gloves.
Never paint over mould without cleaning it first.
7. Anti-Damp Paint: Long-Term Prevention
If your property has areas prone to mould (like bathrooms or cold bedrooms), it may be worth using anti-damp or anti-mould paint. These help prevent the growth of mould and stains.
Tip for Landlords
If you’re renting out a property, you can:
- Include ventilation recommendations in the contract or a tenant guide
- Provide a simple dehumidifier
- Make sure there are no structural problems before renting out
Prevention is cheaper than repairs — and avoids conflict with tenants.
What About Health?
Mould isn’t just an aesthetic issue. It can cause or worsen respiratory problems, allergies, and irritation — especially in children, the elderly, and people with asthma.
That’s why it’s important to act as soon as you spot signs of damp — both to protect the property and care for the health of those living in it.