Firm piles into foundations
‘‘This system is a lot cheaper than many of the repairs and rebuilds we’ve seen. You just need a jack.’’ Nigel Colenso, ABI Piers founder
Christchurch firm ABI Piers has designed a foundation system tailored for lightweight homes.
Founder and designer Nigel Colenso has a background in construction and project management and saw opportunity in the new builds going up around the city.
The foundation system is suitable for all types of land but particularly TC3-zoned land, which is prone to liquefaction and movement. Significant portions of Christchurch are classified TC3 including Fendalton, Merivale, St Albans, Mairehau, Burwood and Parklands near the beach.
Colenso and his son Chris have been working on development, patenting and accreditation of the stainless steel pilings for about three years.
Nigel Colenso observed the rebuilding of several commercial buildings during the post-quake recovery in Canterbury.
‘‘It occurred to me that all these new commercial buildings had base isolation systems so why not residential homes?’’ he said.
‘‘This system is a lot cheaper than many of the repairs and rebuilds we’ve seen. You just need a jack.’’
The stainless steel adjustable piers or piles sit on a concrete base or footing and have bolts so that in the case of future foundation movement they can be adjusted to re-level a lightweight home up to two storeys high.
The piles have an estimated life span of 50 years.
A metal plate at the top of the pile allows the house’s wooden bearers to move in an earthquake and return to the correct position because the pile is tensioned to the bearers with springs.
The Building Research Association has certified the system for its seismic mechanical properties.
‘‘In the opinion of BRANZ the system is fit for purpose and will comply with the Building Code.’’
The Colensos have developed a website and pamphlets explaining the system, and have carried out demonstrations for architectural firms, the Christchurch City Council, and others in the construction sector.
They received favourable feedback at a Canterbury Home Show, and are also members of the Superhome movement dedicated to efficient home building.
Several types of foundation systems have been developed in Christchurch since the 2011 quakes, but the ABI Piers system appears to be among the simplest and easiest to install and adjust.