Use this free online Interstitial Condensation Risk Calculator for walls, roofs and floors.

To estimate condensation and check your build-ups against the Glaser methodology.

The tool is designed for architects, self-builders, energy consultants and contractors working on new homes, extensions and retrofits.

How to Use the Thomas Studio Interstitial Condensation Risk Calculator for Walls, Roofs and Floors

The Thomas Studio Interstitial Condensation Risk Calculator is split into three sections: Wall, Roof and Floor.

For each element:

• Use the drop-down menus to select the material layers, working from the internal (warm) face through to the external (cold) face.
• Enter the thickness of each layer in millimetres.

These presets already allow for Lambda values. If you use them, simply enter the appropriate thickness in mm and do include the VCL air leakage layer and breather membrane layers.

For externally ventilated constructions:

• If you are using a rainscreen cladding system, you do not need to add these layers as they are considered ventilating.
• For ventilated warm roofs you do not need to add these layers as they are considered ventilating.

Once all layers are added, click “Calculate Condensation Risk”. The resulting Interstitial Condensation Risk is shown in the graph panel and summarised at the bottom of table, where they are compared against risk of condensation so you can see whether your design meets, exceeds, or falls short of the standards.

We hope you find the Thomas Studio Interstitial Condensation Risk Calculator useful tool in designing high-performance, energy-efficient buildings.