Thermal breakthrough

BM TRADA thermal modelling trials prove ACTIS Hybrid insulation reduces thermal bridging, outperforming many other products on the market

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Thermal modelling trials carried out by certification body BM TRADA have shown that ACTIS Hybrid insulation products have a dramatic impact on counteracting thermal bridging and act as excellent thermal blankets. The assessment involved measuring and collating psi values for 16 model junctions insulated with vapour control layer HControl Hybrid and breather membrane Boost’R Hybrid.

A follow up SAP exercise carried out by an independent energy assessor to measure the impact of these calculations on a whole building concluded that using Hybrid generated one of the best Y values ever assessed by his firm. Interestingly, the test showed that using the actual psi values calculated by BM TRADA created a far more thermally efficient building overall than when the assessors used the government prescribed default psi values. For example, the default psi value for the eaves to warm roof junction is 0.08, but the model junction modelled by BM TRADA using all three Hybrid products is 0.045.

In another example, using default psi measurements with a 140mm stud wall with a U-value of 0.19 failed the SAP test and required the addition of a wood-burning stove and solar thermal to counteract the effect of thermal losses through the fabric. In contrast, using vapour control layer HControl Hybrid on the construction build-ups necessitated only a 90mm stud wall with a U-value of 0.23 to pass the SAP test.

The results of both analyses confirm that Actis Hybrid multifoils act as thermal blankets and counteract thermal bridging.

For more information and technical support visit: and for the U-value project simulator:



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