The historic church of the Parish of St Wilfrid’s in Kennington, South London is benefitting from an added layer of protection in the form of Roofshield, which has long been recognised as one of the highest performing roofing membrane solutions, providing a pitched roof underlay, which is both air and vapour permeable.
Surveyor Andrew Roche Consulting specified Roofshield for the roof refurbishment, with contractor Churchill Roofing selected to carry out the installation. Like many historic buildings of its type, the complex structure of the roof, with its various shapes covering a range of different pitched areas would have meant that introducing additional ventilation would have proved extremely complicated.
The complex nature of the roof structures of these historic buildings requires careful consideration of moisture management, and condensation control. The majority of vapour permeable underlays use an airtight VP film layer to achieve their performance rather like a Gore-Tex jacket. While water resistant, they cannot completely prevent condensation within the roof space; meaning additional ventilation has to be introduced in order to allow air to circulate.
Roofshield’s patented SMS (Spunbond Meltblown Spunbond) structure allows high levels of airflow, in addition to the transport of moisture vapour, making the formation of condensation in the roof space virtually impossible. It has an extremely high degree of vapour permeability, as well as air permeability, so will still perform in conditions in which air tight alternatives will not.
Roofshield has successfully been used in a wide range of refurbishment programmes resulting in the restoration and preservation of a number of significantly important heritage buildings covering applications such as local authority, education, recreation, housing, and worship including; Belfast City Hall, Derry Guildhall, Hamilton Hall – St. Andrews, Lynn Library Queens University Belfast.
For any building to have an energy efficient, healthy, moisture free building envelope there is a clear need to manage the balance of Heat, Air and Moisture movement (HAMM) throughout the building’s life cycle from design, construction, completion and use.