How to Add Tens or Hundreds of Thousands to the Value of Your Home – Pre-Purchase Inspection Proofing

As an owner of a plaster clad house, you are no doubt aware that these are harder to sell and fetch a lower price than similar traditionally clad houses. The stigma of the leaky building scandal hangs over every single plaster clad house – whether it leaks or not.

When the time comes to sell, you have to convince the buyer, their bank, and their pre-purchase inspector that your house is safe and a good investment.

This can only be accomplished by providing hard evidence that can’t be ignored or rejected. Moisture Detection Company have been looking after, maintaining and improving plaster clad houses since 2005 and their Pre-Inspection Proofing Process prepares your house for the best sale price.

Why You Shouldn’t Re-Clad Your Home

Plaster Clad House Needs Help To Pass Pre-Purchase Inspection

After failing pre-purchase inspections, the owners decided to pull the house off the market so they could address the problems making the house sale fall over. During the process of installing moisture detection probes and analysing the timber samples, the house was found to have a number of moisture issues and decay problems.

No-one is immune from buying a leaky home

Anyone can get caught out buying a leaky home. In this situation, the Real Estate Agent knew the builder who built the building in question. Once it was built the agent sold the property. She then sold the building again – then the third time it was sold she bought it herself. She then found out the building had a high number of leaks and timber damage – from detailing and design problems that were likely there since construction.

This shows that anyone can be caught out by this issue – despite having a deep involvement in the industry.

The lesson for potential buyers of monolithic or plaster clad houses is that they must understand what they are buying.  Many houses look fine to the untrained eye, and even experienced professionals can get caught out and miss signs that lead to expensive mistakes.  Buying a house with monolithic cladding in the height of the summer means that traditional tools used for finding leaks, such as surface scanning moisture meters and thermal imaging can easily miss picking up problems.

Buying a house is likely to be the biggest investment you ever make so make sure that it isn’t also the biggest mistake you ever make.

When Moisture Detection Company installs moisture probes as part of a pre-purchase inspection, we are not only using the most accurate moisture detection system available, and testing for timber treatment, but we are also examining timber samples from every probe location for evidence of decay.

This means that before you finalise your offer, or go through with the purchase, you have actual evidence of leaks, decay and timber treatment.

If you buy a plaster clad house without this, then you are gambling that the house is good.  Can you afford to be wrong?

A recent client had already bought their house – without getting it properly inspected first.  When the moisture probes were installed and the timber analysed the client was then given the bad news that there is extensive decay arising from faulty windows, ranch sliders and flashings.  The red dots signify very bad decay, the orange dots show partial decay.


The wall at one of the locations looked pristine.  No signs of dampness, or damage.  But when we opened it up to see what the probe had found, we saw this.  Moisture Probes don’t lie.  The client now has an expensive project ahead to get the house safe and habitable.  If we had probed the house beforehand he could have negotiated a substantial discount, or just walked away.

Decayed timber found by Moisture Detection Probes




Success Stories

These case studies below are just some of the thousands of properties that have used the proactive building management system to successfully protect and enhance their building and market value. You will see that every one of them is a plaster-clad home and that they have been successfully sold for above their current CV – backed up by the great results we found in their properties using the Mdu Probe System.
Its easy to protect your property value with the Mdu Probe System

Building Expert specifies Mdu Probes

Below is an extract of a high-ranking Building Expert specifying Mdu Probes as part of targeted repairs and to protect timber from extensive damage from future leaks:

“MONITORING: If the targeted repairs option is selected, and there is a possibility of your continuing to live in or own the apartment, I would recommend you have a permanent monitoring system installed as soon as possible. A system such as that offered by Moisture Detection Ltd (Mdu Probe System) is likely to identify the needs for additional repairs, and can provide early warning of problems and a chance to carry out repairs before extensive framing damage takes place.”

Additionally, should the owners choose to follow a full reclad approach to their building remediation, then they would be well advised to install the Mdu Probe System as an excellent method to do the same thing – to check on works and address any future leaks that may happen in the future and provide total peace of mind for the current and future owners.

Purchasers pull out when vendor is unwilling to have the Mdu Probe System installed

Below is a recent case where the purchasers of a plaster home were seeking assurances as to the condition and health of the property. Their investigations and advice led them to request the Mdu Probe System be installed as part of their due diligence. However the vendors refused and the purchasers are now prudently taking their business elsewhere, for the reasons explained by the purchaser in the below email:

From: David (PURCHASER)
Subject: RE: Mdu PROBE System for “xxxxxxx”

Hi there,

Just to let you know the sale has fallen through.
The vendors have refused to allow us to do due diligence (i.e. install the Mdu Probe System), as recommended by our inspectors and legal representative. Two reasons were presented by the owners:
1) the probes are too invasive, and
2) that we might use the results to insist that remedial work is completed.

We can only assume that they either have something to hide, or don’t understand the realities of selling a plaster clad house in NZ.

Thanks for your time. We will now look at other properties.


Plaster home stigma may cost NZers more than actual leaky home issues

The construction of a generation of leaky buildings was a huge, and still unexplainable embarrassment for which no-one has been held to account.  There are many cases of badly damaged houses where owners have inherited major problems that need urgent and extensive repairs. These owners may or may not have had the ability to receive some compensation but almost always end up out of pocket to some extent.

However even more worrying, is that the message of “recladding is the only way” of fixing problem houses is wiping BILLIONS off the value of the remaining built infrastructure of our country through “leaky building stigma” – and this dwarfs the cost of the Christchurch rebuild. Unless this path and message are corrected, then ordinary NZers will continue to lose their wealth, retirement fund and nest eggs. Cumulatively this will mean NZers will be over $15 billion dollars out of pocket.

Put in perspective, this cost dwarfs the income generated by the planned SOE sell-down (estimated $5 – $7 billion – ). Why would a country sell off its public assets for $5 – $7 billion at the same time as letting the remaining private residential assets be devalued by over $15 billion? It doesn’t make sense.

While there are many technical issues surrounding this debate, the reality is simple: not all plaster clad buildings have major issues requiring reclads. There has been a dramatic over-estimation of the number of buildings and size of the problem, which is fanning the flames of fear and condemning perfectly good homes. It has been proven factually time and time again that most buildings do not have major problems and can be easily looked after with the help of the right technology and approach. Also, there are reliable ways to discern problem houses from good ones with certainty and without damage ( – giving home purchasers certainty that they can buy with confidence.

However, this is not the message the public is being fed, and with devastating effects. Along with the Christchurch earthquake rebuild, the biggest economic issue facing the country is not in how problem buildings are being expensively remediated – it is the “reclad them all” rhetoric that is condemning and DEVALUING ALL of the tens if not hundreds of thousands of plaster-clad NZ homes that in fact do not need extensive remediation. The mums and dads investors of these houses are now victimised and faced with the impossible situation of having hundreds of thousands of dollars wiped off the value of their sound buildings – yet there is no major physical damage or problems.

Many of you or someone you know will own a plaster-clad home from what is defined as the “at-risk” time period – from 1992 to 2004. “Official estimates” are arguing that 90% of these plaster-clad buildings need to be completely reclad – irrespective of how well they’re performing. But a much lower percentage actually have this level of problems – and the rest are being unfairly tarred with the same brush.

This issue touches many many people across New Zealand. This is not specifically a “building” problem, and it’s not specifically a “housing” problem, what this issue revolves around is more of a “property” and “investment” problem – and the erasing of hard-earned value in our infrastructure that NZers are being duped into devaluing and rebuilding. These homes are also typically the major asset in a family so their wealth evaporates. This must stop.

While this is contrary to the “official position”, this argument has the backing of a large number of professionals in the building industry right across the board who can speak from personal experience.  They are involved with all aspects including investigation, maintenance, targeted repairs, partial-reclads and full-reclads.

The rights of the hundreds of thousands of property owners and the protecting the generated wealth of the nation is at stake. This has been and will remain an issue of significance for many years for plaster homeowners. Over $15 billion will be wiped from New Zealand’s bottom line and remove any benefit state asset sales will have to New Zealand’s financial position. This is an issue that the government needs be taking very seriously as it starts to sell down its prime assets to make ends meet – unless the leaky home stigma problem is addressed quickly more and more NZers will continue to lose their life savings for no good reason.

Fascias-style guttering leak internally

Taylor Fascia-style gutters causing water to run into the building

Guttering can be a hidden leaky building danger particularly for plaster clad homes

Klass or Taylor fascia style guttering overflows is a significant source of leaks causing decay in houses, especially plaster clad homes with direct fixed cladding which then can’t dry out easily.  These houses are often built with untreated or undertreated timber which then rots.

The perfect storm that culminated in the ‘leaky home’ fiasco was caused by a number of products and processes being introduced into the NZ housing market with totally inadequate testing, validation or approval.  High on this list is the Klass or Taylor Fascia style guttering. Because of their design and defects in installation, blockages from leaves can cause overflows into a building.

Moisture Detection Company have used their patented Moisture Probe System to identify decay and thousands of leaks in houses which can be directly attributed to this disastrous design.  If the leaks are not found early enough, the decay can cause extensive and expensive damage.

In the house where the picture below was taken, we found large parts of the internal framing of the back wall rotted away behind the gib because of persistent overflows of the gutter.

Decayed Timber

Timber Decay Caused by Leaking Taylor Fascia.

Fundamentally, the problem is that the internal lip of the gutter is lower than the external lip so that when the gutter overflows, the water can run across the soffit (if there is one), and into the wall and ceilings.

Moisture Detection Company use their patented Mdu Moisture Detection Probe System to investigate and provide hard evidence on the moisture, decay and timber treatment condition of monolithic plaster clad houses.  Contact us on (09) 271 0522 to discuss how we can help you.

Often, where a valley in the roof runs into the gutter, the internal edge is notched even lower which becomes the first overflow point. If there are any blockages, excess rainwater during a heavy rain will overflow back into the house, often without the owner being aware.

Taylor Fias

Where the valley in the roof meets the gutter, this is often a leak point.

If you are buying a plaster clad house with Taylor fascia, you must find out whether this is leaking, or has leaked in the past and caused decay in the walls.  Only the Moisture Detection Company can find this with minimal visible damage to the house.  Visit our Contact Us page.

This is a particular problem for owners of plaster clad houses built from 1992 to 2004 where there is unlikely to be a cavity allowing the water to drain away, and the timber is likely to be untreated or undertreated.

Most people aren’t aware that the decaying leaves which block gutters and downpipes house particularly aggressive decay fungi which can cause accelerated rot when overflows wash it into the house.  The standard boron treatment cannot stop many of the nastier NZ fungi species.

In traditional externally-mounted guttering systems, these are designed that if there is a blockage somewhere, water will overflow away from the building. This does no harm to the building and will alert the owner to a problem.

Taylor Fascia style gutter may look quite attractive but how could anyone have ever thought that they were a good idea?  Yet this was installed on tens of thousands of houses.

What can you do if you have Taylor Fascia?

Ideally, replace it to get rid of the risk and make your house easier to sell – all pre-purchase building inspectors should know the dangers and will warn prospective buyers.  While you are at it, add some eaves if you don’t already have them.

If you don’t want to replace the gutters then there are steps you can take to reduce the risks of leaks and decay.

  1. Install a Mdu Moisture Probe monitoring system – a very small investment for protecting your biggest asset.  Following a full probe installation, you will know where your house is leaking, if there is decay and if the house is built with treated timber.  The probes are then a ‘leak early warning system” for your house. With this information, you can plan the next step.
  2. Cut down any trees that may drop leaves on the roof and check the gutters regularly for blockages. If you can’t get rid of the trees then consider some type of leaf guard system or clean the gutters more regularly.
  3. Inspect your full guttering system for defects that could lead to leaks – many systems are just badly installed but you don’t see the leaks unless they are really bad- but regular small leaks into your walls will destroy them eventually. Moisture Detection Company can inspect and carry out some repairs.
  4. Install Mdu Hi-Flo overflows at critical points around the guttering.  Moisture Detection Company will recommend where these should be installed to allow water to overflow to the outside, instead of into your house, if the gutter tries to overflow.

Moisture Detection Company inspect, diagnose problems with, monitor and repair houses with monolithic cladding for leaks and decay. We are the experts at keeping your house safe and dry – without needing an expensive re-clad.

Contact us today for an informal discussion on your situation.  We promise professional, friendly and ethical advice.

Phone:  (09) 271-0522


Serving owners of Plaster Clad homes twenty years.