E2 Solutions for Barrier Wall Cladding

To comply with the building code, claddings must shed water. Hitex is a barrier type cladding designed with flexibility to withstand normal building movement. Hitex will not let wind driven rain through the barrier – it is the penetrations and other assembled building components that let water in behind the Hitex, causing damage.

Solution One – Ground lines
Applications: Minimum clearances to be strictly observed. No Hitex to be concreted in. Hitex withdraws any applications into the ground including “P” grade applications. Water clearances are necessary to avoid soaking into the cladding, or sucking through capillary action, exposing the bottom plate and studs to moisture and rot. Do not leave clearance between the Hitex and slab otherwise water can bounce up and wet the bottom plate. Keep 60mm overlap to the slab.
Solution Two – Window Mitres – a full undersill tray
Application: All windows with mitre joints must have a full undersill tray with the ends and back turned up and front turned down to deflect water out over the sill flashings. This tray must be the full width and length of the window. This to be fitted prior to window installation. Mitres are sealed by gappng compounds that fail and this allows water in behind the cladding causing extensive rotting and toxic moulds to form.
Solution Three – Soffits
Application: All roof gutters installed enclosed within the fascia and above the soffit must be discontinued. Secret and hidden type gutters must be discontinued. All soffits must be fitted with holes to allow occasional water on the soffit through overflowing gutters or broken tiles to shed away from the wall cavity.
Solution Four - Protrusions
Application: No timber protrusions to be installed Timber moves significantly through climate cycles and sealants are incapable of maintaining cohesion with exterior claddings. Moisture enters through capillary at these points and is unable to exit. Hang ribbon plates or joists on sealed sleeved brackets.
Solution Five – Pipes and Wires
Application: All external pipes and wires to be flanged by the plumber or supplier of the pipes and wires. Cracks and splits in sealants around pipes allow wind driven rain to capillary into the timber frame for rot to set in.
Solution Six – Treated Timber
Application: Until BRANZ and the BIA independently verify that untreated timber is acceptable as framing, use only treated timber that can withstand rot and toxic mould growth. Any water getting in behind the cladding will be trapped between painted gib board and painted waterproof claddings. Even with Cavity Systems the timber must still be durable enough to withstand rot and fungi at least until the leak is found, stopped and the wall dries out.
Solution Seven – Balconies and Decks
Application: Ranch sliders and doors must be “set down” and allow for a water proofing membrane coming up and under ranch sliders, leaving adequate room under the ranch slider flange for tiles and grout, and clearance for cladding. Care must be taken to waterproof all timber framing and floor area at door recesses to balconies and decks by taking the membrane up the “set down” and across the floor under the ranch slider. Often tiles are installed above the flange on the ranch slider meaning water can pump in under, to the timber floor and frames. This is not acceptable.
Solution Eight – Electrical Meter Box
Application: Meter boxes to be manufactured with flanges so they can be flashed in the same manner as windows. At present no flashing provisions are made. It is not acceptable to rely on sealants in these areas.
Solution Nine – Bathrooms
Application: Bathrooms must be adequately ventilated to reduce moisture and prevent the increase of moisture content in wall cavity . All building materials in walls are permeable. Excessive moisture build-ups in the framing must be minimised especially in these high, relative humid areas.