Multifoil insulation: giving you a warm reception

Multifoil insulation: giving you a warm reception

The Problem: How to provide insulation that would seal roof-level draughts, and not cause a condensation risk?

The former Lister Lane special school in Bradford was built in 1914 and designed with fresh air in mind as an ‘open air’ school with lots of ventilation, large windows and glass-walled corridors to contribute to staying healthy at a time when tuberculosis was rife. Although it closed in 2010, it was included in Bradford Council’s refurbishment programme to update their properties, and was to have a new role providing respite care facilities for young people with disabilities.

Upgrading thermal performance

tlx silver multifoil with PIR insulationThe upgrading was carried out in phases, and an important requirement was that the thermal performance be improved. Since the roof itself was sound, the initial proposal was to install rigid foam board between the joists of the original ceiling, plus some Rockwool to be laid on top of the suspended ceiling below.

Avoiding a potential condensation risk

However, it was realised that having Rockwool on the suspended ceiling would make the void above so cold that there was the risk of condensation occurring, as the moisture produced by the activities in the room below migrated upwards.

Instead, PIR board was used between the joists, with TLX Silver fitted below on the warm side of the build-up, providing air and vapour-tightness. The suspended ceiling was removed so as to expose the previously hidden windows, providing more light into the rooms, and the windows were also replaced to improve both the insulation and ventilation.

An additional benefit of TLX Silver’s shiny low emissivity outer surfaces is that not only does it reflect the heat back into the rooms below, but in summer it reduces the amount of heat being radiated into them, maintaining a comfortable environment at all times of the year.Tlx silver multifoil used in conjunction with PIR insulation board

The Solution: 

TLX Silver – the fully BBA-certified vapour control layer – provides airtightness and reflects heat back into the interior, whilst also minimising solar gain in summer.

Click to view our LABC registered TLX Silver solutions

Click to view our blog based on this solution 


tlx multifoil technical helpline