Condensation can often be an ironic consequence of improvements designed to enhance the comfort of our homes. While insulation, draught proofing, and double glazing reduce heat loss, they also reduce ventilation, increasing the relative humidity inside your property. Everyday activities—like running a bath or drying clothes indoors—add moisture to warm air. When that moist air meets cold surfaces or when the property cools, condensation occurs, potentially damaging surfaces.
Mould growth is often associated with condensation; however, condensation is not necessary for mould growth to occur.
Mould spores exist in large numbers in the atmosphere; to germinate, they need nutrients, oxygen, moisture, and an ideal temperature. Sources of nutrition, particularly wallpaper, leather, clothes, etc., are widespread in buildings, and the internal environment provides a suitable temperature for growth.
Oxygen is always present, so mould growth is particularly dependent on moisture conditions at surfaces and the length of time these conditions persist. Moulds can germinate and grow if the relative humidity at a surface rises above 80%. This is considerably less severe than the 100% (dew point) required for surface condensation to occur.
As the internal surfaces of external walls are colder than the air temperature within the building in winter, the relative humidity in the boundary layer of air at the wall can be significantly different, especially in solid wall buildings, and is often 5-10% higher than in the middle of the room.
Common indicators include:
✔ Water running down windows
✔ Damaged decoration
✔ Black mould growth
✔ Unpleasant, musty damp smells
At Olympic Surveyors, we know that condensation issues can be both concerning and stressful. A condensation survey involves much more than observing surface moisture—it’s about understanding the complex interplay of factors that cause both surface and interstitial condensation.
What Our Survey Involves
Comprehensive Assessment
Our surveyors use the right equipment to record moisture vapour levels, heating performance, thermal values, vapour barriers, and ventilation efficiency.
Expert Diagnosis
By understanding how these elements interact, we pinpoint the exact causes and provide the most effective solutions to improve internal air quality and reduce condensation risk.
Surface Condensation
Definition:
Occurs when water vapour in the air turns into liquid as a material’s temperature falls below the dew point (e.g. condensation on a cold beer glass).
Interstitial Condensation
Definition:
Happens within the layers of a building’s structure—such as inside floors, walls, roofs, and insulation.
Consequences:
Warm, moisture-laden air passes through a surface and cools down within the structure. This creates a condensation point at the dew point temperature, increasing the risk of mould, deterioration of the property fabric, fungal decay, and even corrosion of building elements and services.
Moisture Vapour Levels
Assessment
Understanding the amount of moisture present in different areas relative to the external environment is crucial.
Heating Systems
Efficiency & Distribution
Consistent temperatures help prevent cold spots where condensation can form. Evaluating how well the heating system mitigates temperature variations is vital.
Thermal Values
Building Material Performance
Walls, floors, and ceilings with poor thermal performance may dissipate heat less effectively, leading to cold spots and potential condensation.
Vapour Check Membrane
Role
This crucial component controls moisture movement within building structures, reducing the risk of condensation, mould growth, and material damage.
Ventilation
Importance
Adequate, properly calibrated ventilation is critical in controlling indoor moisture levels.
Standards
Surveyors examine systems in light of Part F Building Regulations (Volume 1: 2021) and British Standard 5250, ensuring that moisture-laden air can escape effectively.
Our experienced surveyors at Olympic Surveyors are equipped with the knowledge and tools needed to assess every factor affecting condensation. By carefully analysing moisture levels, heating, thermal properties, vapour barriers, and ventilation, we deliver precise diagnoses and tailored recommendations to effectively mitigate condensation issues.
Trust Olympic Surveyors for a thorough and informed approach to condensation surveys. We are committed to safeguarding the health and longevity of your property by addressing the root causes of condensation—not just its symptoms.
Olympic Surveyors: Your Trusted Partner for Condensation Solutions
Specialist Surveyors with expertise in cavity wall assessments.
Multi-award-winning PCA members , regulated by RICS.
State-of-the-art diagnostic tools ensuring accurate results.
Tailored remedial solutions for long-term property protection.
If you suspect wall tie failure or structural movement, contact Olympic Construction Ltd for a professional wall tie inspection.Early detection and expert remediation ensure the stability and longevity of your
