Base / Weep Flashing

316L stainless base weep flashings are installed at the base of every storey (or at the base of the building) in a rainscreen cladding system to collect and drain any water that has entered the cavity. The slotted weep holes (10 mm × 3 mm or 10 mm circular at 450 mm centres) allow water to escape while minimising insect entry. The flashing turns up minimum 50 mm against the substrate (upstand) to prevent water tracking back. In multi-storey buildings, a base weep flashing is required at every floor level where the cavity is closed by a fire barrier — allowing the lower section of the cavity to drain independently. 316L stainless provides 50+ year maintenance-free service in marine and coastal zones.

Factory-folded 6063-T5 anodised aluminium base weep flashings with 316 stainless insect mesh behind the weep holes. The insect mesh prevents entry of ants, wasps, and small insects into the cavity while maintaining drainage — critical for cavities that also contain thermal insulation, as insects nesting in insulation degrade its thermal performance. The aluminium flashing is suitable for coastal zones (200 m–1 km from ocean). The weep holes are spaced at 450 mm centres; at every fire barrier location, the base weep flashing is installed on both sides of the barrier to drain each independent cavity section. Class 2 anodising (20 micron) provides 25–40 year service in coastal zones.

Colorbond Ultra base weep flashings are colour-matched to the building's Colorbond palette — suitable for residential and light commercial cladding in general and coastal zones (C1–C4). Factory-folded with weep holes at 450 mm centres, the flashing drains the cavity at the base of each cladding panel run. Colorbond base weep flashings are commonly used in residential Colorbond Walling installations as part of a coordinated flashing set (head, sill, jamb, and base weep all in matching Colorbond colour). Available in 27 standard Colorbond colours. Cut edges must be primed with zinc-rich primer within 24 hours of cutting on site.

Base weep flashings with integrated cavity closers provide both the drainage function and the cavity termination at the base of the cladding system. The cavity closer prevents termite access into the drained cavity — important in high-risk termite zones across eastern Australia. The weep holes allow water drainage while the cavity closer profile blocks insect access. Must comply with NCC 2022 Part B3.2 (Resistance to Subterranean Termite Attack) in Termite Risk Categories M, H, and VH. Available in anodised aluminium or SS316 depending on corrosion zone. Must be used in conjunction with a compliant chemical or physical termite barrier below slab.