When viewing a property, it is easy to be reassured by fresh decoration, tiled walls and cosmetic improvements. Unfortunately, building surveys frequently reveal that some of the most serious defects are hidden beneath the surface. Damp remains one of the most common problems we find in Spanish homes.
The instinctive response is often to seal the damp inside the wall. External walls may be covered with ceramic tiles, waterproof coatings or non-breathable paints. While this can provide temporary relief, it often worsens the problem. Moisture that would normally evaporate becomes trapped within the wall, increasing internal dampness. Eventually, plaster fails, paint flakes and tiles lose adhesion and fall away.
Traditional buildings were designed to “breathe”. Lime renders and breathable mineral paints allow moisture to evaporate naturally. By contrast, impervious materials lock moisture into the structure, encouraging mould, staining and long-term deterioration. Decorative external tiling, often installed to protect walls from rainwater splash, can actually force moisture further into the building. A far better solution is to install effective guttering, downpipes and drainage systems to direct water away from the structure.
Many older properties lack effective damp-proof membranes, waterproofing to retaining walls and proper floor construction. Rising damp and lateral moisture penetration are therefore common. In our experience, poor workmanship means some modern buildings suffer from similar problems. Covering blistering paint, flaking plaster or salt deposits does not remove the source of the moisture. The cause must be identified and addressed. Removing damaged finishes, allowing walls to dry naturally, improving drainage and installing appropriate damp-proofing measures are usually essential first steps.
Humidity problems are often compounded by poor thermal performance. Many older homes have little insulation and single-glazed windows. As temperatures fluctuate between day and night, condensation forms on cooler surfaces, increasing humidity and encouraging localised mould growth. The result is an uncomfortable living environment, together with high heating and cooling costs.
Older services can present additional concerns. Electrical installations may have been altered over the years and may not meet current safety standards. Cables embedded in damp walls can create further risks. Rural properties supplied by private wells should have water quality checked regularly and buyers should ensure that older lead pipework is not present.
Properties relying on cesspits or septic tanks also require careful investigation. These systems should be located, inspected and emptied of non-biodegradable material regularly. Buyers should also ensure that foul drainage cannot contaminate any well water supply.
Finally, planning status should never be overlooked. A property may appear long established yet still have unresolved registration, licensing or planning issues that can lead to significant legal and financial complications. Thorough legal checks should be combined with a professional building survey.
The lesson is simple: decoration can hide defects, but it cannot cure them. Before buying an older property, ensure that damp, insulation, drainage, electrical safety, water supply and planning status have all been properly investigated. By knowing a property, prevention is better than repair.
