Part C - Condensation Risk

Part C - Condensation Risk Analysis

Building Regulations Part C - Condensation Risk Analysis

What is condensation risk analysis?

Condensation risk analysis as detailed in approved document part C, is becoming an increasing need in the construction industry as traditional construction methods and new architectural designs may adversely lead to the formation of mould growth and associated health problems.


We can assess the likelihood of surface and interstitial condensation, and offer solutions based on design plans and data taken from thermal modelling and building material data.

Surface Condensation

Surface condensation occurs on visible surfaces and contributes to mould and surface staining which can usually be alleviated with correct installation and use of ventilation.

Interstitial Condensation

Interstitial condensation occurs in between layers of a construction, such as inside roof, wall and floor elements. This can lead to gradual degradation of the construction materials, and reduce the long-term safety of a construction, along with increased chances of mould growth and reduced air quality.

We use software packages such as Build Desk and THERM, to produce 2D/3D models of the details under assessment and can gain insight into the possibility of condensation and remodel the detail to include a solution.

These assessments allow us to calculate the predicted dewpoint temperature which will vary dependant on the materials used in the construction and environment conditions such as humidity and temperature differential from outside to inside.


We can carry out an assessment and predict the chances of condensation occurring and offer solutions and design alterations which can prevent this in the planning stage.

Vapour control layers positioned on the warm side of insulation and replacing old materials with new often help resist condensation and ensuring that cavities have ventilation will also make an impact.


Very little remedial action can be taken to alleviate interstitial condensation and the cost of replacing major building elements may be huge.


Please give us a ring or request a quote and ensure that unpredicted condensation does not ruin your development.

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