By SJH Surveying Services – Chartered Surveyor (MRICS)
Damp is one of the most common concerns raised in UK homes, yet also one of the most misunderstood. Many people assume damp equals “rising damp”, but in reality, most issues stem from condensation, poor ventilation, leaks, or trapped moisture — especially in older properties.
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Older Homes Behave Differently
Traditional solid-walled buildings were designed to breathe. When modern materials like cement render, gypsum plaster, tanking systems or injected DPCs are added, moisture often becomes trapped, causing blown plaster, mould and persistent damp readings.
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Condensation Is the Biggest Culprit
Most damp patches in homes today are caused by:
- Lack of extractor fans
- Poor airflow
- Cold external walls
- Furniture pushed tight against walls
- Inadequate loft or underfloor ventilation
Improving ventilation and heating patterns often resolves issues quickly.
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Injected DPCs Often Don’t Work
In solid walls, chemical injections rarely solve damp. If salts are present or moisture is trapped behind cement-based repairs, damp simply reappears. The cause is usually external defects or lack of breathability — not the DPC.
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Salts and Historic Plaster Issues
Old chimney breasts, salts in plaster, and historic moisture can cause damp staining even when the wall is structurally dry. Lime plaster is usually the most appropriate repair for traditional buildings.
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What Surveyors Look For
During a survey, SJH Surveying Services checks:
- Roofs, gutters and rainwater goods
- Ground levels and bridging
- Ventilation (extractors, air bricks, loft vents)
- Materials used (gypsum vs lime)
- Leaks around kitchens/bathrooms
- Chimneys, flues and historic salts
This ensures the true cause is identified.
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The Right Fix Depends on the Building
Modern homes: often bridging, leaks, or cavity issues
Older homes: breathe, don’t block, avoid cement and tanking
Good airflow, appropriate materials, and proper maintenance are key.
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Need Help?
SJH Surveying Services offers Level 2 & Level 3 Surveys, damp investigations and specialist advice on traditional and listed buildings across Shropshire, Worcestershire and the West Midlands.
