Mould & condensation
Condensation control
Assessment of moisture production, ventilation, heating and insulation to reduce surface condensation.
What the issue is
Condensation occurs when moist internal air meets a surface below its dew point. It is the most common cause of domestic dampness and mould, and is usually addressed through ventilation, heating and insulation rather than chemical treatment.
Common symptoms
- Water on window glass and frames
- Mould in corners, behind furniture and on ceilings
- Damp bedding, curtains or wardrobes
- Musty smells
- Worse in colder months
Likely contributing factors
- Insufficient background ventilation
- Extract fans absent, undersized or not working
- Intermittent or low heating
- Cold bridging at junctions
- High internal moisture production
Conditions that may be mistaken for it
- Rising damp on ground-floor walls
- Penetrating damp on external walls
- A slow plumbing leak
- Construction moisture in new work
How the issue should be investigated
- Record temperature, relative humidity and dew point
- Measure surface temperatures at affected areas
- Test extract fan performance
- Review background ventilation provision
- Consider occupancy and heating patterns
Potential treatment or repair options
- Improved mechanical extraction to bathrooms and kitchens
- Positive input ventilation or heat-recovery systems
- Background ventilation improvements
- Insulation improvements at cold spots
- Practical guidance on heating and moisture control
When treatment may not be appropriate
- Where mould is limited and simple ventilation changes will resolve it
- Where a building defect is the real source of moisture
Factors affecting the cost
- Number and type of ventilation units
- Electrical alterations required
- Access to lofts and external walls
- Making good and decoration
What to expect during an inspection
The surveyor will take psychrometric readings, test existing fans and discuss how the property is used and heated.
Final recommendations always depend on the property, the inspection findings and the confirmed cause. Elevated readings alone do not confirm rising damp, not every mould problem requires extensive treatment, and damp-affected plaster does not always need replacing.
Frequently asked questions
Next step
Not sure which inspection you need? Start with a few questions.
Tell us what you are seeing and we will set out what is likely, what is uncertain and which inspection would answer the question. Speak to us on 0333 335 6152 if you would rather talk it through.