Domakihub How to Prevent Damp and Mould in Your Home
Stop moisture problems before they start with these practical steps for homes, rentals, and hotels.
Reviewed by Domakihub home & decor pros · 2026-06-23 · 5 min read
Damp and mould are among the most damaging — and most preventable — problems in any property. In Greece's climate, where warm humid summers meet poorly insulated winter walls, moisture has countless ways to creep in. The video above walks through the underlying science; the steps below give you a hands-on action plan you can follow in your home, holiday rental, or hotel room right now.
Why Damp Is Such a Problem in Greece
Greece's Mediterranean climate feels dry, but coastal humidity, seasonal rainfall, and sun-baked masonry that cools rapidly at night create near-perfect conditions for condensation and rising damp. Older construction — stone walls without cavity insulation, flat terraces without proper waterproofing, and single-glazed aluminium frames — lets moisture bridge the gap between outdoors and indoors with little resistance.
For holiday rental owners and hoteliers the stakes are even higher: guests notice mould before almost any other maintenance issue, reviews suffer, and structural damage compounds silently between seasons.
Understanding the Three Types of Damp
Condensation forms when warm, moisture-laden air hits a cold surface — the most common cause in Greek homes, especially in winter. Rising damp draws ground moisture upward through walls that lack a damp-proof course, typically appearing as a tide-mark up to one metre high. Penetrating damp enters through cracks in render, failed flat-roof waterproofing, or leaking gutters and appears as irregular wet patches that grow after rain.
Identifying which type you are dealing with shapes every decision that follows. A damp meter and a close look at the pattern and timing of the problem (does it worsen after rain or after cooking?) will usually confirm the source.
5 Steps to Keep Damp and Mould Out
- 1
Ventilate every moisture-producing room daily
Cooking, showering, and even breathing release litres of water vapour into the air every day. Open windows for at least ten minutes after these activities, or run an extractor fan until steam clears completely. In bathrooms without external windows, a humidity-sensing fan that switches on automatically is a worthwhile investment. Never block existing air vents, even in winter — they exist to move moisture out.
- 2
Control indoor humidity with a hygrometer
Aim to keep indoor relative humidity between 40 % and 60 %. A cheap digital hygrometer placed in the living room gives you an at-a-glance reading and removes the guesswork. If it consistently reads above 65 %, a portable dehumidifier running for a few hours a day — especially in bedrooms and living areas during winter — will bring levels down before condensation settles on walls and windows.
- 3
Insulate cold surfaces to raise their temperature
Mould grows where surfaces stay cooler than the surrounding air, because that is where moisture condenses first. In practice this means insulating the inner face of external walls using thermal board or an external render system, fitting double-glazed frames, and insulating flat-roof slabs from above. Even adding heavy curtains lined with thermal fabric reduces heat loss from glass and raises the surface temperature enough to stop nightly condensation forming on window sills.
- 4
Seal and waterproof the building envelope
Walk around the outside of the property after a heavy rain and look for water staining, cracked render, or blocked gutters and downpipes. Repoint any open mortar joints, seal roof-terrace parapets with a flexible waterproofing membrane, and clear gutters at least once a year. Inside, re-grout and re-silicone bathroom and kitchen joints every few years — hairline cracks are enough to let water soak into the wall behind tiles over many months.
- 5
Act immediately on any visible mould
Mould spreads: a small patch treated today is far less costly than a colony left until next season. Scrub surface mould with a diluted white-vinegar or sodium bicarbonate solution, dry the area thoroughly, and apply a mould-inhibiting paint or primer before redecorating. Critically, also address the moisture source — cleaning mould without reducing humidity or fixing a leak guarantees it returns within weeks. For large infestations affecting structural materials, call a specialist rather than attempting DIY removal.
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FAQ
- Is damp more common in summer or winter in Greece?
- Both seasons present distinct risks. Winter brings cold external walls that cause condensation where they meet humid indoor air, particularly in coastal and mountain properties. Summer brings high ambient humidity and warm rain that can penetrate render cracks or flat-roof seams more aggressively than cold-season drizzle. Holiday rentals are especially vulnerable during summer occupancy gaps when buildings are closed and unventilated for weeks at a time.
- Can a dehumidifier alone solve a damp problem?
- A dehumidifier manages the symptom — excess moisture in the air — but it cannot fix a structural leak or inadequate ventilation on its own. It is most effective as a short-term intervention while you identify and resolve the root cause, or as a seasonal tool in rooms where ventilation is limited. Running one continuously without addressing the source will push up your electricity bill without achieving a lasting result.
- How do I stop mould coming back after I clean it?
- Mould returns whenever moisture and a food source (dust, paint, plaster) are present together. After cleaning, apply a mould-resistant primer and specialist anti-mould paint, which contain fungicides that inhibit regrowth. More importantly, reduce the humidity in that room through better ventilation or heating — a cold, damp room repainted with standard emulsion will grow mould again within a season regardless of how thoroughly it was cleaned.