Wellington (New Zealand’s capital) is situated alongside Wellington Harbour and is home to many museums, theatres and arts festivals and is a leading centre for creative industries, such as film and computer technology. It is also the new location for the New Zealand Stock Exchange (NZX) which is situated inside the historic Odlins building in the business district’s waterfront.
Originally built on reclaimed land (allowing the railway to be extended in 1893) in 1907, the Odlins building was home for C&A Odlin Timber and Hardware Co. It was once situated right next to the water and among the interiors impressive features are two huge timber trusses spanning the width of the attic floor. In 2001, plans began to retrofit one floor of apartments, four floors of office space, a ground floor retail area and a basement car park inside the heritage four-story building.
The biggest challenge faced by both the contractors (LT McGuinness) and architects/engineers (Athfield Architects, Dunning Thornton) was that the Odlins building was older, bigger, wetter and more rotten than most. “…there has been a lot of interest to see what we do to keep the heritage elements, and also modernize it…” says LT McGuinness.
Structural work and repair began on the building in January 2004, and once frame work to support the building was complete, work on the basement began. Contractors were literally swimming since the basement was submerged under 1.5 m (4.9 feet) of water. An additional challenge to this was because construction was below sea level and required meticulous planning in dealing with tides.
To ensure the building’s new parking garage would remain leak-free, LT McGuinness needed a concrete waterproofing solution that would provide a watertight resistance to hydrostatic pressure and could also protect against ingression of tidal pressure. McGuinness looked to Fraser Brown & Stratmore Limited for a crystalline waterproofing solution. Technical Sales Manager, Jeremy Mallender recommended Kryton’s Krystol waterproofing system.
Kryton’s Krystol Internal Membrane (KIM) was used because of its resistance to both tidal waters and hydrostatic pressure from any direction. Tests have shown that “Krystolized” concrete can hold back hydrostatic pressure with up to 140 meters (460 feet) of water head pressure.
When added to a concrete mix or applied to existing concrete, Krystol creates a chemical reaction that causes needle-like crystals to grow, filling the spaces between concrete particles and permanently blocking the movement of water in all directions. If small cracks later form, incoming water causes additional crystals to grow, self-sealing the cracks and stopping the movement of water through the concrete. The Krystol Crack Repair System and Krystol T1 & T2 Waterproofing System were also used to stop leaks in areas of the basement where KIM had not been used.
Six months have passed since the Odlins building’s completion in June 2005. Today it remains an historical and iconic reminder of the past, resurrected and leak-free.