How We Carry Out a Thorough Damp Survey
Every survey we carry out follows the Federation of Damp's 7-Step Survey Method — the certified methodology behind our FODCS qualification. It exists for one reason: to stop treatment being recommended before the actual cause has been established. Here's exactly what that looks like, step by step, and every tool involved.
Inspect, test, diagnose, then recommend — in that order
The Federation of Damp built this method specifically because the same avoidable mistakes keep showing up across the industry: leaning too heavily on a moisture meter reading, mistaking condensation for rising damp, skipping the external inspection, or recommending a treatment before the property has actually been properly investigated. The method exists to make each of those mistakes structurally harder to make. A treatment is never proposed until a diagnosis has been reached, and a diagnosis is never reached until every step below has been completed.
Client brief & property background
We start by understanding your concerns, how long the problem has been present, any previous treatments the property has had, and how the property is occupied and used day to day. This isn't paperwork — it's the context that shapes where we look first.
External inspection
Before we look at a single symptom indoors, we check outside: ground levels against the damp-proof course, brickwork and pointing condition, render, roofing elements, and rainwater goods. Most damp problems originate outside the building, so this comes first, not last.
Internal visual inspection
Staining, tide marks, mould growth, salt contamination, blown plaster, timber defects — how the damp is actually presenting, and where. This gives us the pattern we need to interpret everything that follows.
Moisture testing
We map moisture readings at different heights and locations to build a picture — but a meter reading supports the diagnosis, it never determines it in isolation. Readings that don't match the visual pattern get investigated further, not taken at face value.
Ventilation & environmental assessment
Airflow, humidity, extractor fans, cold bridging, heating and occupancy patterns. This is the step that actually catches condensation — the single most commonly misdiagnosed type of damp — because condensation is an environmental problem, not a structural one, and it won't show up correctly if you only look at the wall.
Diagnosis
Everything gathered so far — defects, environment, moisture pattern, construction type — gets weighed together to reach one logical, evidence-based conclusion. Not a guess informed by one reading, a conclusion built from all of them.
Recommendations & reporting
A clear written report explaining what we found and why, with recommendations proportionate to the actual evidence — not a menu of upsold extras. If the answer is "you don't need a damp-proof course," that's what the report says.
The tools we use, and why each one exists
Every tool below plays a specific, limited role. None of them is designed to give a standalone verdict — that's exactly the assumption that leads to damp being misdiagnosed across the industry.
Moisture meter
Two distinct modes: "search" mode uses radio frequency and reads non-invasively to around 20mm depth, but can be affected by interference; "measure" mode uses pins to complete an electrical circuit — more specific, but notorious for false positives from salts or nearby metal. A screening tool, not a verdict.
Thermal imaging camera
Doesn't detect water — it detects temperature differences. A cold patch on a thermal image flags where to look closer, fast, but it needs interpreting alongside everything else, not read on its own.
Borescope
A small lens on a flexible stem with its own light source, letting us see inside cavities, floor voids and behind finishes without removing anything invasively.
Hygrometer
Measures relative humidity, dew point and ambient temperature. This is the tool that actually catches condensation risk — relative humidity consistently above around 70% points to a real problem regardless of what a wall moisture meter says.
Calcium carbide ("Speedy") test
A more rigorous, quantitative test of total moisture content in a sampled material — used where the screening tools disagree or the stakes of the decision are high, though it still can't separate active water from salt-bound moisture on its own.
Salt analysis
Tests directly for nitrate and chloride contamination in the wall, rather than inferring it indirectly from how a meter is behaving — the only way to properly confirm or rule out hygroscopic salt contamination as the real cause of a recurring patch.
This is the process behind every survey we carry out — not a sales visit with a meter.
Book a Damp Survey →Frequently Asked Questions
A structured process: understanding your concerns and the property's history, a full external inspection, an internal visual inspection, moisture testing, a separate assessment of ventilation and humidity, and only then a diagnosis — followed by a written report with proportionate recommendations.
Because most damp problems originate outside — a defect in guttering, render, pointing or the damp-proof course itself. Understanding what's happening externally first gives real context to whatever's found indoors, rather than guessing backwards from the symptom.
It detects temperature differences, which often correlate with damp areas and help identify exactly where to focus closer investigation. It's a fast way to narrow down suspect areas, not a standalone diagnosis.
Because condensation — the most commonly misdiagnosed type of damp — is caused by the internal environment, not a structural defect. Measuring humidity and ventilation separately is what actually catches it, rather than mistaking it for rising or penetrating damp.
A clear explanation of what was found at each stage, the reasoning behind the diagnosis, and recommendations that are proportionate to the actual evidence — not a list of treatments recommended regardless of what the survey found.