What effect can wind forces have on a facade’s breather membrane?

Lightburne on Murphystown Way is a new residential development in the Leopardstown area of Dublin. When complete, it will provide 254 apartments. The mix of one- and two-bedroom dwellings are spread across three buildings, which range from four to thirteen storeys in height. KM Lynskey were appointed as specialist contractors, and given responsibility for specifying and installing the facade build-up.

In addition to meeting Ireland’s nearly-zero energy building (NZEB) regulatory requirements, the Lightburne site was notable for a high wind velocity. This put the onus on component specification, making sure products would be able to withstand the rigours of site without suffering damage or compromising the finished building performance.

Wraptite external air barrier was chosen as the vapour permeable (“breather”) membrane for the facade, as part of the complete wall build-up put forward by KM Lynskey. The membrane provides the required levels of vapour permeability and airtightness. Meanwhile, its patented adhesive technology and self-adhered application offered reassurance that high wind speeds would not risk damaging the
membrane installation.

“Compared to other breather membranes, Wraptite is much quicker to install and easy to work with. Our teams are very happy with it.”
Cristian Diac – Contracts Manager, KM Lynskey

However well-sequenced a facade installation is, there will inevitably be periods of time where the breather membrane is exposed to the elements. During these times, it’s important that the membrane isn’t damaged as a result of wind actions.

For obvious reasons, remedial work to repair a damaged membrane is undesirable. It adds to the contractor’s material costs, and risks adding delays to the project if extensive patching or repair is needed.
Furthermore, while damaged areas of membrane will be clear to see, it’s impossible to know if other areas of the installation may have been weakened in some way, without showing physical damage.

If damaged membrane is left unrepaired then the building faces having an as-built performance deficit compared to the intended design. Vapour permeability and energy efficiency in the finished facade could be severely compromised, especially if the membrane was also specified as an external airtightness line in the facade.
Methods of membrane attachment vary: from mechanical fixings, which do not secure the whole surface area, to those which require substrate priming, which adds an extra installation step that needs to be done correctly.

It is perhaps unsurprising, therefore, that our self-adhered Wraptite® external air barrier is increasingly popular, and particularly well-suited to windy sites like Murphystown Way.

Wraptite is a self-adhered, vapour permeable membrane that provides a consistent airtight seal, helping to manage moisture movement and reduce condensation risk in the facade, while contributing to meeting a project’s airtightness target.

Wraptite adheres well to a variety of substrates – including timber, cement, steel and various sheathing boards – without needing primers, sealants or tapes. Its patented adhesive technology has been trusted on projects worldwide for over 15 years, and Wraptite has been BBA certified for over a decade.

KM Lynskey were already using Wraptite on two other projects in Dublin so, as a company, they had some familiarity with these benefits and experience of working with it. Nevertheless, it was important to make sure the operatives on site at Lightburne understood how to get the best out of Wraptite. Proctor Group’s Regional Sales Manager, Tony Ruth, delivered a toolbox talk at the start of the project.

“We recorded the talk, to make sure we could deliver the same message to all operatives,” said Cristian Diac, Contracts Manager at KM Lynskey.

“We then built a sample area of facade on site. This is something we do on every project, and it acts as a benchmark for all detailing steps.”

Tony visits site monthly to carry out a site observation report, which KM Lynskey then share with architects O’Mahoney Pike.

“Two years ago, we were using a different breather membrane,” added Cristian. “Compared to that product, Wraptite is much quicker to install and easy to work with. Our teams are very happy with it.”

“Lightburne features an excellent Wraptite installation by KM Lynskey,” said Tony Ruth. “By using a self-adhered membrane, they haven’t had to worry about the membrane flapping and tearing on site and avoided the need for patching to damaged areas of membrane.”