L17: Leaky Buildings Flashcards
What is a leaky building?
One that allows water to penetrate the building envelope –> held inside the wall cavity –> festers and raises moisture content in framing –> fungal growth –> weakens timber and increases mould (health issues)
What are the common features of a leaky building?
Modern/Mediterranean style
Monolithic cladding (barrier approach to prevent water coming in but cannot get water out in failure)
Parapets (no eaves)
Typically multi-storey terraced housing
What percentage of WHRS claims have monolithic cladding?
85%
When did monolithic cladding peak in the Auckland market and why?
2001-2002 at approx 35%
Low cost, easy installation, low maintenance
What contributed to the origin of leaky buildings?
1990s - market liberalisation of construction industry
Removal of apprenticeship training scheme
Performance based building codes
Competition between councils and private certifiers
What are the 4 Ds of weathertightness
Deflection
Drainage
Drying
Durability
What percentage of WHRS claims came from Auckland (May 2013)
77%
What are the key locations of leaks?
45 including parapets, headers of openings, balconies, cladding itself
How did the percentage of stucco and EIFS properties compare to percentage of WHRS claims for these types?
6% stucco, 17% EIFS
Yet majority of WHRS claims
How did the percentage of clay brick properties compare to percentage of WHRS claims for these types?
38%
Yet very few of WHRS claims
What percentage of susceptible building stock is expected to fail in NZ? (PWC study)
11-22%
What are the greatest types of costs making up remediation? (PWC study)
71% repair
17% legal
What is the estimated total hard costs to the economy? (PWC study)
$11-23 billion
= 7-15% of GDP
What are the indirect costs of leaky buildings and what are they estimated at?
Health problems caused by toxic black mould and mental health (depression/stress)
Estimated at $474 million
What is leaky building stigma?
Perceived risk that certain features are more susceptible; no proof that it is leaky but decreases number of potential buyers