Condensation Risk Calculator

Condensation risks can compromise structural integrity, indoor air quality and occupant comfort. Managing moisture within the building fabric plays an important role in preventing condensation risks. Our Condensation Risk Calculator can assess the likelihood of surface and interstitial condensation, helping your projects meet the latest industry standards.

Designed to work alongside U-value calculations, this free online tool aids designers, specifiers and contractors in making informed decisions about insulation, ventilation, and air and vapour control layers. This helps reduce the risk of costly issues arising later in the construction process.

Why is condensation risk analysis important?

Condensation can occur when warm, moisture-laden air meets cold surfaces, leading to damp patches, mould growth and potential material degradation. The risk of condensation depends on several factors, including:

• Airtightness and ventilation performance
• Internal humidity levels influenced by occupant activities
• Vapour permeability of building materials
• The effectiveness of insulation and thermal bridging minimisation

To address these concerns, the BS 5250:2021 standard outlines best practices for moisture management, emphasising the importance of early-stage condensation risk analysis.

How does our Condensation Risk Calculator work?

Our online tool utilises the Glaser method, the industry-recognised approach for condensation risk analysis in vapour-closed constructions. It follows a straightforward layer-by-layer process to assess temperature and humidity conditions within the building fabric, determining whether condensation is likely to form at any point. What you’ll need to input:

• Construction type and material layers
• Project location for external temperature and humidity data
• Intended occupancy type for internal moisture conditions

The calculator integrates with our advanced U-value calculation tool, providing in-depth moisture risk assessment in one simple process.

What are the benefits of using the Condensation Risk Calculator?

Quick, accurate results – Save time with condensation risk assessments. Industry-compliant analysis – Follows BS 5250:2021 and BS EN ISO 13788:2013 guidelines. Optimised for U-value integration – Seamlessly evaluates both thermal performance and moisture risk. Designed for all professionals – Useful for architects, engineers and contractors. Supports best-practice design – Prevents costly errors and contributes towards long-term durability.

When should you use the Condensation Risk Calculator?

Whether designing a new build or upgrading an existing structure, condensation risk analysis should be an integral part of the planning phase. Our calculator is particularly valuable when:

• Selecting insulation materials for cavity walls, roofs and floors
• Upgrading traditional buildings with modern construction elements
• Integrating Air and Vapour Control Layers (AVCLs) in vapour-closed constructions
• Ensuring compliance with building regulations and best-practice standards For complex projects or cases requiring a dynamic analysis of moisture movement, we recommend consulting specialists or using advanced tools such as WUFI® analysis.

Get started with our free online condensation risk tool today!

Ready to help your designs be moisture-resistant and built to last? Use our Condensation Risk Calculator today to generate a detailed risk assessment for your project.

The Glaser method assumes steady-state conditions and does not account for factors such as moisture storage, wind-driven rain, or solar drying. For construction types requiring in depth analysis, or if you need expert guidance, our technical support team is available to provide tailored advice.

Start your condensation risk analysis and U-value calculations now.