Module 3 · Types of Damp in Detail
3.1 Condensation in Detail
8 min read
Condensation accounts for more damp complaints in UK housing than every other mechanism combined, and it is the one most often reported as something else. This lesson gives you the full diagnostic picture — formation, pattern, risk factors, and the measurements that turn a hunch into a finding.
Learning objectives
By the end of this lesson you will be able to:
- Explain how surface and interstitial condensation form.
- Recognise the distribution pattern condensation leaves in a room.
- Identify the building and occupancy factors that drive it.
- Assemble the evidence needed to state condensation as a probable cause.
Key terms
- Surface condensation
- Moisture forming on a visible internal surface that is at or below the room's dew point.
- Interstitial condensation
- Condensation forming inside a construction where vapour reaches a cold layer within the build-up.
- Moisture generation rate
- How much water vapour the occupants add to the air, typically 10–15 litres a day for a family.
- Cold bridge mould
- Growth following the geometry of a thermal bridge rather than the shape of a defect.
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Read the rest of Types of Damp in Detail
Module 1 is open to everyone. The remaining six modules — building science, each damp mechanism in depth, meters and thermal imaging, the full inspection method, and report writing — are free too. We just ask for an email so you can pick up where you left off, and so we can send your certificate when you finish.