Self Builder Sees Simplicity of i3
illbruck's i3 system used at Furzefield Farm
Bryan Hart is building a six bedroom home for himself and his family on a property in a rural area, where sensitive detailing was as important an aspect of gaining permission as structural strength and energy performance. Mr Hart though was determined to make his construction as eco-friendly as possible, and sought a sealing system which could accommodate the oak frame’s characteristic movement.
He explains: “We are doing a demolition and rebuild of some old and not very nice, 1950s agricultural cottages at Furzefield Farm, replacing them with a six bedroom home which features a made to measure oak frame from Welsh Oak, erected over a twin wall concrete basement from a German specialist, adding a lot more space.
“While externally the elevations show brick, we are lining the walls with Kingspan insulation and Fermacell reinforced gypsum boards to achieve a U-value of 0.26 W/m2K. However, because of oak’s tendency to continue moving long after it is erected, I was concerned about sealing the windows which are coming from Ladymead Joinery and some large leaded lights from Bronze Oak Casements, located in the hall.
“What struck me about the Tremco illbruck i3 system is the three different ways it solves the problems of water ingress or weather-tightness, air leakage and insulation. I was shown a model on the stand at the exhibition, which explained perfectly how it works: a version of which I have used to help educate the tradesmen on the job about what we are trying to achieve.
“Tremco’s area manager has also given us superb support on site and we are expecting to pass the air leakage test quite easily. Ladymead is now taking the system on board for their own use because they can see what a superior and much cleaner method it is compared to the normal route of just spraying filler foam.”
When utilising the i3 system, the window frame is wrapped using the Duo membrane with the overlaps being rollered to ensure full contact. The window can then be fitted in place and plumbed before the selected thickness of Compriband is inserted from the outside to take up the remaining gap.
Flexible filler foam can then be injected around the interior side of the reveal, taking care not to overfill the joint. And finally the Duo membrane is turned back and lapped under the window cills and boards to seal the internal air barrier. This completes the i3 system’s triple barrier to air leakage although, crucially, it remains vapour permeable.
