News Article

Condensation Risk Analysis

Condensation Risk Analysis

Before we talk about condensation risk analysis, it is worth going into more detail about what condensation is and the different types that can affect buildings.  Condensation is the process of water vapour in the air condensing from a gas into a liquid. In buildings it occurs when warm moisture-laden air meets with cold vapour-resistant surfaces. There are two main types of condensation: surface and interstitial condensation.

Surface Condensation

Surface condensation is condensation which occurs on the visible surfaces of a construction, rather than between the layers. Internal surface condensation can promote mould growth, thus reducing indoor air quality, as well as creating unsightly pattern staining. Thermal bridges can undermine effective insulation and can contribute to the formation of surface condensation as the heat is drawn out, leaving the inner surface cold.

Interstitial Condensation

Interstitial condensation is condensation which occurs between layers of the construction, i.e. ‘inside’ the roof, wall or floor elements. Interstitial condensation can cause deterioration or even failure of the components of the assembly, potentially shortening their useful lifespan. It is important to ensure an element is designed to avoid interstitial condensation, or to create an adequate ventilation solution to remove any condensation that forms.

why is a condensation risk analysis important to carry out?

Insulation products such as spray foam insulation are installed by people who want to improve the energy efficiency performance of their property, whether that is a domestic, industrial or commercial building. Condensation impacts on the effectiveness of this insulation so it’s important to make sure that the money being spent is going to produce the desired results.

what is a Condensation Risk Analysis?

A Condensation Risk Analysis can be performed to look into any potential condensation when installing insulation. This analysis is undertaken in accordance with BS5250:2006 and looks at the building components, the order in which they are appear in the construction, the use of the building and its location (using met office data for the area).

This analysis is performed alongside a u-value calculation and can be undertaken by Isothane’s technical team to help you in planning your projects insulation work.  More information on our u-value calculation service can be found here or contact our technical service team with any queries you may have.



Newhouse Road,
Huncoat Industrial Estate,

General Enquiries

Tel: +44 (0)1254 872555Email:

Sales Enquiries

Tel: +44 (0)1254 872555Email:

Technical Enquiries

Tel: +44 (0)1254 872555Email:

Prepolymers & Export Enquiries

Tel: +44 (0)1254 872555Email:


Enter your email to receive latest newsletters and industry updates

This website uses Cookies to improve your browsing experience. View Cookies Policy

I'm fine with this