How to stop condensation happening

Achieving the right retrofit solution to condensation at an acceptable cost can be a challenge due to Building Regulations which often require an improvement to the energy efficiency of buildings.

Where more than 25% of a wall is re-plastered, re-rendered or re-clad then Building Regulations approval is required, and the process often requires the fitting of additional insulation.

Adding insulation internally or externally requires careful planning to ensure that surface condensation does not occur due to thermal bridging. Thermal bridging occurs around junctions where there is an interruption in the insulation.

SBS Travis Perkins is now offering a series of standard construction details free of charge to help minimise the fabric’s contribution in RdSAP, thereby helping you reduce costs. By using the Retrofit Standard Construction Drawings, savings of over £450 can be made to the annual costs of heating a building, and the energy performance certificate (EPC) rating can be improved from band E to band B.

Detailed thermal modelling of each junction was undertaken to optimise the performance of the building fabric; reducing energy bills, CO2 emissions and condensation risks. The drawings have been independently tested by the BRE to ensure there are no thermal bridging and surface condensation issues.

Condensation case study

In one case an existing wall was computer modelled with the addition of internal wall insulation. Whilst this improved the performance of the wall, a lack of attention around the window presented a condensation risk to the internal facade. To address the surface condensation issue, additional insulation was added to the underside of the sill which increased the overall performance of the wall and removed the condensation risk.

Cost effective solution

This example highlights the value that the Standard Construction Drawings can bring, as they are the culmination of a series of experiments which present a cost-effective solution for architects and builders working to improve the energy performance rating of an existing dwelling without creating unwanted side-effects.

Visit www.sustainablebuildingsolutions.co.uk/resources to download PDFs of the drawings free of charge. You can buy the same as DWG files to allow seamless integration into AutoCad drawings.

Also read How to avoid condensation.