When insulating from the inside is not an option
Older houses can present challenges when upgrading to modern building standards as ever more stringent U Value requirements need to be met. Older buildings can benefit greatly from insulation – it results in increased energy efficiency, reduced damp presence, elimination of condensation risk and an increased EPC rating.
But these also tend to be among the hardest to insulate owing to their various methods of construction. As was the case for social housing in the London Borough of Southwark. This area is home to some of the wealthiest businesses in London, alongside world renowned landmarks such as the Shard and the Tate Modern. However, it also has the highest proportion of social housing in the county. When the local council was tasked with the upgrade of pre-WW2 social houses to make ‘every home warm, dry and safe’ they were keen to address the lack of insulation. This proved to be a considerable challenge, as the upper flats were very cold with boarded roof constructions. Unable to work from the inside, the council needed a fix that would cause the least amount of disruption for the tenants, whilst providing the greatest thermal benefit.
With prospective restrictions in terms of access, the main contractor needed a workable solution. So in conjunction with our technical department and the local branch of Minster, a non-invasive, and therefore satisfactory solution was agreed.
How the Gold standard is achieved? 
As the roof could be raised, it was possible to apply TLX Gold 2-in-1 insulating breathable membrane above a 50mm counter-batten. The use of TLX Gold aids towards a thinner PIR board which is required to meet building standards. It has a glossy surface underneath that reflects heat and improves the R value of the unventilated air layer underneath it. A single layer of TLX Gold was used as internal access was limited and additional insulation could not be used. This method combines a breathable membrane with insulating properties, and achieved a U value of 0.69W/m2K - a substantial improvement.