The superior airtightness performance of the Wraptite membrane from A. Proctor Group is delivering huge benefits to both the in-factory and on-site construction of a series of new modular social housing for Anglesey Council.
Wraptite is the only self-adhering vapour permeable air barrier certified by the British Board of Agrément (BBA). Applied externally on the outside of the structural frame, it simplifies the process of maintaining the envelope’s integrity, as there are less building services and structural penetrations to be sealed.
The high vapour permeability of Wraptite allows the substrate beneath to dry quickly and moisture vapour to escape, and reduces the likelihood of mould, mildew, condensation, timber distortion and metal corrosion. The self-adhesive nature of Wraptite means that it is easy to apply together with Wraptite corners and there is no requirement for mechanical fixings.
Specialist contractor Kenton Jones was commissioned by the Isle of Anglesey County Council to construct the new homes using a high-performance timber frame system. He explained how Wraptite was key to achieving a quality airtightness solution which was suited to modular build.
He said: “After 10 years of building an open panel high-performance timber frame system, we moved to a factory insulated closed panel system, which had the airtightness and VCL applied in the factory and simply taped on-site. This worked well when the airtightness layer was fully accessible before services were installed on-site.
“In 2019, we built a new module factory and delivered our first set of modules in early 2020. It was then we realised internal airtightness was going to be a difficult detail. When building modules that are fully factory finished internally, but need to be craned together on-site to form the same dwelling, both in a vertical and horizontal joint, we identified that there would be areas of the building which would remain inaccessible after installation on-site.”
Kenton continued: “The first stage of the project was supplied with internal airtightness applied off-site that had very technical, vulnerable details to continue the airtightness around the dwelling within the small access areas left for finishing on-site after installation. This method proved very time consuming in the factory swapping from our usual airtightness board to flexible airtightness membranes between the modules. The cost of this was not sustainable, so we needed to look for an alternative.
“We chose Wraptite to achieve the low value airtightness we required for the module system. The benefits of having the airtightness layer externally were a huge saving in time in the factory and impressive simplifying of details to achieve the same quality results. Wraptite was installed off-site in a factory environment for speed and ease and simply taped together on-site between modules to achieve the airtightness.”
“Overall we saved time and money with Wraptite, we now have a set of high performance technical details for the airtightness in our module system, which are easy to achieve and help maintain a robust quality control system.”
