week 17 unitec carpentry 3 - 5 august 2011

week 17. start of semester 2. our last task in semester 1 was to line the external wall frames of the whole house in building wrap. when we returned, we checked that the wrap was still intact. then we begin to install cavity battens 45x20mm at every wall frame stud, except where the braceline straps will go. these will provide a continuous cavity from top to bottom behind the weatherboards. we also rout back the battens to about 15mm thickness at the base and install vermin proof drainage channels at the base flush to the boundary joists. plus uPVC flashings at both the internal and external corners. we also cut back the wrap from the window openings.fold the wrap back to the frame and staple. then we installed flexible building tape at the tops of the window heads and all along the sill per manufacturer's specifications.

building wrap is used to line the external wall frames of the whole house, including the gable ends. min 300 vertical and horizontal laps are essential to prevent water ingress. blue straps are stapled at intervals to prevent insulation batts pushing out the wrap.

photograph shows external corner of house with cavity battens and corner uPVC corner flashings installed over building wrap. note aluband flexible tape and orange uPVC corner mouldings over sill and top corner of window.

building wrap is cut out and folded back into window opening. aluband flexible tape is then fixed to top corner of window opening per manufacturer's specifications.



cavity battens around a window; note routed end to batten to fit vermin proof drainage channel over aluminium head flashing