Water In Buildings Flashcards
Absolute humidity and relative humidity
What happens to absolute and relative humidity levels as temperature changes?
Molecules of water as vapour in warm and cold air diagram
Dew point diagram
Condensation in 1 m³ of a diagram:
Condensation amount possible in typical house as it cools diagram:
Temperature gradient in typical room diagram:
Why condensation is often worse in corners – moisture matters. Diagram:
Another reason why condensation is often worse in corners-shape matters. Diagram:
Example of a cold bridge – insulated cavity wall with traditional masonry cavity closure. Diagram:
Interstitial Condensation.
Water vapour moving by diffusion through a structure diagram:
Conditions required for timber decay diagram:
Effects of house being constructed with mixed materials to the walls diagram:
Hygroscopic materials and contain salts and contaminants which may be present in buildings due to several causes:
Diagnosing dampness
1. Investigation
- What symptoms do you see?
- What measurements do you take?
- What questions do you ask?
Diagnosing dampness
2. Analysis
- What courses are you considering?
- Compare your findings with those expected for all causes
- discount causes that don’t match information gathered
Diagnosing dampness
3. Conclusion
- Identify causes that much information gathered
- identify further investigations
- Identify remedial works / action required 
Analysing types of dampness:
Condensation (surface):
Analysing types of dampness:
Condensation (intersticial):
Possible factors or symptoms:
Analysing types of dampness:
Penetrating dampness:
Possible factors or symptoms:
Analysing types of dampness:
Rising dampness
Possible factors or symptoms:
Analysing types of dampness:
Service leaks/spillage
Possible factors or symptoms
Analysing types of dampness:
Flooding/groundwater
Possible factors or symptoms:
Analysing types of dampness:
Hygroscopic materials
Possible factors or symptoms
Analysing types of dampness:
Construction moisture
Possible factors or symptoms:
Analysing types of dampness:
All types of dampness:
Possible factors or symptoms:
The defects of timber due to attack by wood boring insects
Dry rot fungus - key indicators
Managing dry rot - traditional approach:
