Repair at Any Cost? – Why Would You?

December 16, 2013

By Greg O’Sullivan

Damage, decay and mould caused by leaks often are concealed by external and internal wall cladding from homeowners and investigators alike.  It takes very specific and destructive investigation by fully trained and qualified building surveyors to find the problems.  Most frequently the true extent and location of decay, mould and other problems cannot be discovered until all cladding is fully removed.

Toxic mould and loss of structure is a serious future risk for occupants.  Therefore well-founded knowledge; established and proven investigation techniques; thorough sampling and support from competent outside testing agencies are the foundation stone of any sound repair.

We all know that Doctors and Specialists in the medical field have decades of experience and wisdom to call from.  Regardless they still add to that knowledge by checking, sampling and obtaining reports by outside testing agencies.  A similar depth of knowledge and experience is required to understand building leaks and dilapidation; how to recognise the potential extent of the problem and how to follow this up with solid support data.

Often, unfortunately for homeowners, this is not the case.  Less experienced or inadequately qualified consultants are at times hell bent on convincing homeowners that the problems is not as bad, or that there are cheaper solutions, or worse – all that is needed is sealant and a thick coat of paint.

These solutions would be wonderful if they worked or were true but they don’t and are not correct.  These solutions are a fallacy built on false wisdom and false economy.  They are supported by a lack of knowledge, inadequate experience of taking samples for testing and poor back-up support, or still worse samples taken that will provide misleading results.  The solutions of these consultants are built on hope rather than wisdom.  They use the sophisticated con of potential savings in repair costs but do they actually save money?  They do not!

If the only problem someone has got is with a ranchslider that leaks and all it needs is to be resealed then that is all that is required.  That is not what I am talking about here.  What I am talking about is the hidden insidious, invasive damage over broad areas of buildings that are the hallmark of leaking buildings.

I have noted houses and multi-units being repaired over the last two years that have failed again and more substantial repair are required.  Actually the money that should have been spent the first time is now needed to be spent for a second time.  The easier way to state this, is that if $100,000 was spent doing target repairs and 18 months to two years later it fails, then those owners now have  not only paid that $100,000 but likely another $200,000 for a full reclad.  They are now out of pocket $300,000 or $100,000 overspent.

Who in their right mind would put $100,000 into a drain and flush it away.  Well those who accept inadequate repair and who years later are faced with a correct repair have done exactly that.

Please note direct fixed claddings do not come close when compared to a properly designed drain vented cladding system.  Why?  Simple really, the cladding is spaced off the framing – there is a gap and water is kept away from the framing.  Water can drain out quickly and get away.  According to research by BRANZ scientist, Mark Bassett drying will be between two to four times faster in the cavity space than when water is trapped directly behind cladding.  Also testing the cladding has shown the likelihood of success with flashings in a cavity system is increased several times.  Not only do the systems work better, they also keep any potential water away from the framing.  They provide a dry future environment.  They help deal with the risks of future problems with moulds and decay that are left behind in microscopic form from the repair process.


Decay to cantilevered boundary joist that many consultants would leave in place
It can be even worse. Often with inexperienced operators, or those with little knowledge leave extensive decay and toxic moulds deliberately behind the so called ‘repaired cladding’.

Professor Aino Nevalainen from the National Public Health Research Program reported to the “ Leaky Buildings – What do we know about the health effects?” Otago University Medical School seminar in March 2008 that a recent Finnish study found two school building repairs that showed that the fully repaired building overcame its bio-contamination. While a partially repaired school was found to be slightly more contaminated after repair than it was before repair.

The person giving you advice should be trained and experienced over a number of years and should follow the guidance documents for remediation published by the Department of Building and Housing.  Their findings should be supported by sound testing, their solutions must be robust and they should be looking for methods of approach to reduce costs, not doing less work or patch ups, or covering problems over with paint.  If someone states  “let’s do less”, or “I have new ways to save you money” – be suspicious.  If someone tells you they want to cover it over with thick paint – show them the door because they do not know what they are dealing with.

My advice is if you can afford to repair do so as quickly as you can.  If you can’t then you need to seek redress to gain money back from the outset from others.  Seek experienced legal advice.  Whatever you do, do not fall into the trap of spending money once cheaply only to be caught with having to spend the same amount and more two years down the track.

Greg Greg O’Sullivan is the founding director of Prendos Limited and an expert in the area of building failure and in particular, weathertight issues and has, in the past, highlighted to the industry many of the material failures occurring with products used to clad buildings. He is a BRANZ Accredited Adviser, Registered Building Surveyor, Immediate Past President of the Institute of Building Surveyors, Fellow of the Arbitrators’ and Mediators’ Institute of New Zealand and sits on both Mediation and Arbitration Panels and is on the Advanced Panel for Mediation with LEADR.

You may also like

Presenting Our New Prendos Associates

Presenting Our New Prendos Associates

Case Study: Conspec Structural Upgrade

Case Study: Conspec Structural Upgrade

Exploring the Benefits and Costs of Mass Timber Solutions

Exploring the Benefits and Costs of Mass Timber Solutions

Meet with us

If you’d like to talk to us about an existing building, new build project or future property venture, get in touch. We’d love to find out more about your objectives and help you achieve the best possible property solution.

Contact Us.

0800 773 636)

[email protected]

Business Hours.
9am - 5pm

  • This field is for validation purposes and should be left unchanged.

Copyright 2022, All Right Reserved

Prendos New Zealand Limited