Damp and Moisture Surveys: Identifying Hidden Problems
Damp is one of the most common issues we identify at Hampstead Surveyors during property inspections. Understanding different types of damp, how surveyors detect moisture problems, and appropriate treatment options is essential for property buyers and owners in Hampstead and across London.
Types of Damp in Properties
1. Rising Damp
Rising damp occurs when ground moisture rises through brickwork via capillary action. Most properties built before 1900 have no damp proof course (DPC), making them vulnerable. Signs include:
- Tide marks on walls (typically up to 1 meter high)
- Decaying skirting boards and plaster
- Musty smells
- Salt deposits on wall surfaces
- Peeling wallpaper and paint
2. Penetrating Damp
Penetrating damp results from water entering through external walls, roofs, or windows. Common causes include:
- Failed pointing in brickwork
- Cracked rendering
- Defective roof coverings
- Blocked or leaking gutters
- Bridged cavity walls
- Failed window seals
3. Condensation Damp
Condensation is often misdiagnosed as rising or penetrating damp. It occurs when warm, moisture-laden air meets cold surfaces. Contributing factors:
- Inadequate ventilation
- Poor heating
- Modern living (cooking, bathing, drying clothes indoors)
- Sealed windows without trickle vents
Condensation typically appears as mold growth in corners, behind furniture, and in bathrooms.
How We Detect Damp
Our chartered building surveyors use professional equipment and expertise to accurately diagnose damp:
Moisture Meters
Calibrated electronic moisture meters measure water content in building materials. We take readings at multiple points to establish patterns and severity.
Thermal Imaging
Infrared thermal cameras reveal cold spots indicating moisture or heat loss. This non-invasive technology detects damp even when not visible to the naked eye.
Visual Inspection
Experienced surveyors identify telltale signs: staining patterns, salt efflorescence, material decay, and odors. We inspect externally and internally to determine damp sources.
Treatment Options
Rising Damp Treatment
- Chemical DPC injection: Silicone-based damp proof course injection (£40-£60 per linear meter)
- Physical DPC: Inserting plastic membrane (more expensive but effective)
- Replastering: Using breathable lime plaster after DPC installation
Penetrating Damp Solutions
- Repointing: Replacing failed mortar joints (£60-£90 per square meter)
- Render repairs: Patching or replacing external render
- Gutter repairs: Cleaning, repairing, or replacing rainwater goods
- Window resealing: Replacing failed seals around windows
Condensation Management
- Improved ventilation: Installing extractor fans, trickle vents
- Adequate heating: Maintaining consistent temperatures
- Dehumidifiers: Reducing moisture levels
- Lifestyle changes: Covering pans when cooking, opening windows
Common Damp Misconceptions
Myth 1: All Damp Needs Chemical Treatment
Many damp problems result from poor maintenance (blocked gutters, failed pointing). Fixing the source is often simpler and cheaper than chemical treatments.
Myth 2: Damp Proof Course Injection Always Works
DPC injection is effective when correctly diagnosed and installed. However, it won't solve penetrating damp or condensation issues.
Myth 3: Victorian Properties Always Have Damp
While older properties lack modern DPCs, proper maintenance and breathable materials keep many Victorian homes dry.
Why Professional Damp Surveys Matter
Incorrect diagnosis leads to ineffective treatments costing thousands. Our RICS surveyors:
- Accurately identify damp type and source
- Distinguish between similar symptoms
- Recommend appropriate treatments
- Provide realistic cost estimates
- Prevent unnecessary expensive work