Street smart

With car stacker machinery occupying the Ironbankbasement, good waterproofing was a priority. Allco Agencies was contracted to provide a waterproofing solution that could also withstand the rigours of the structural Shotcrete installation.

Allco director Peter Stevens says structural Shotcrete, a widely used construction method for large, below-ground foundation walls, is not always compatible with blindside waterproofing.

"Inconsistent application of Shotcrete onto the waterproofing membrane and the high velocity of Shotcrete can dislodge the waterproofing or blow open the seams," Stevens says. "To avoid this, Allco provided a systematic approach for the design team, Shotcrete applicator, approved waterproofing applicator and the independent quality assurance inspector. This systematic approach, which was supported by the Allco specification and independent waterproofing inspection, ensured the property owner received a watertight building."

Stevens says Volclay Voltex® was specified for the waterproofing. This sodium bentonite-based membrane is needle punched between two geotextiles to produce a furry finish on the poured or Shotcrete face.

"The fur bonds with the concrete and becomes part of the structure," he says. "The Volclay sodium bentonite is transformed into a thick, self-healing, water-impermeable gel."

Stevens says the specifications were put together with assistance from several architectural firms and Cetco, the manufacturer of Volclay.

For more information, contact Allco Agencies, PO Box 101903, North Shore 0745, phone (09) 448 1185, fax (09) 448 1186. Website: www.allco.co.nz.

Story by: Trendsideas