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Damp Surveys: Independent vs Free — Which to Trust

January 18, 2028
4 min read
By MCFAR Group

The free damp survey offered by chemical-injection companies usually concludes you need chemical injection. Independent surveyors more often diagnose condensation, leaks, or breathability problems — all of which have different remedies.

The three main South African damp problems

Penetrating damp

Water entering from outside — failed pointing, blocked gutters, defective rendering, broken flashings, ground levels above DPC.

Rising damp

Groundwater rising through capillary action. Genuine cases exist but are much rarer than chemical-injection companies claim. Often misdiagnosed.

Condensation

Warm moist air condensing on cold surfaces. The most common South African damp problem. Cause: lack of ventilation, cold walls, inadequate heating.

Why "free" surveys mis-diagnose

Surveyors employed by chemical injection companies are commission-paid on installation work. Their job is to find rising damp. Common errors:

  • Moisture meter readings on plaster (which conducts when salts present) misread as damp
  • Cold surfaces (condensation) misdiagnosed as rising damp
  • Tide marks from old historic damp interpreted as active
  • Recommendation: chemical DPC injection (R60,000–R160,000) when problem was a leaking gutter (R4,000)

Independent survey

SACPVP-qualified or SAICE-qualified surveyor with no installation interest. Methods include:

  • Visual inspection of external sources
  • Calcium carbide testing (true moisture content)
  • Salts analysis
  • Hygrometer (humidity) readings
  • Thermal imaging

Cost: R8,000–R18,000 typically.

Remediation by diagnosis

  • Penetrating: fix the external defect, dry out
  • Rising damp (if genuine): chemical DPC injection or membrane
  • Condensation: ventilation, dehumidification, heating consistency, anti-mould treatment

Heritage and breathability

Solid-wall and lime-built buildings need breathable repair systems. Modern impermeable renders, plasters, and chemical injections trap moisture and worsen problems.

MCFAR works with independent damp surveyors on heritage and modern buildings.

Need expert engineering on your project?

MCFAR GROUP has been delivering structural engineering, building, and plumbing services since 1998. Talk to our team about your build, retrofit, or renovation.

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Frequently Asked Questions

Is rising damp real?

Yes, but rare — most South African buildings have an effective DPC. Always rule out other causes first.

Should I trust a damp guarantee?

Guarantees only cover the work specified. If the diagnosis is wrong, the guarantee is worthless.