The popular misconception that ‘leaky buildings’ must be re-clad to stop the leaks is wrong and is being pushed by re-cladding companies and councils to suit their own agendas.  Many home-owners are unnecessarily spending a fortune, thinking that they don’t have a choice.

In this article, we discuss the mature alternative that leaves more money in the pocket of the homeowner and doesn’t subject them to the stress and disruption of re-cladding.

All Houses Leak!

There have always been numerous places where water may leak into a building which why traditionally, houses were built with three layers of protection:

  • the framing was treated with boron to a level where the expected leaks did not cause damage,
  • external framing was required to be ventilated with cavities, so wet framing could dry out following leaks and repairs,
  • windows, doors, decks and penetrations had to have proper flashings to keep out the water.

A series of unfathomable decisions then led to a progressive reduction in building durability and weathertightness:

  • from 1992, houses had less treatment protection to the framing and between 1998 and 2005 often had untreated external wall framing,
  • consents and Certificates of Code Compliance were given to houses without cavities and without adequate flashings or adequate means of preventing leaks.

The result was wet, unprotected framing that stayed wet and decayed….then the leaky homes scandal erupted.

Now all monolithic clad or plaster clad houses are tarred with the stigma that they might be leakers or rotting and that they should be worth less money.

A whole industry has emerged, promoting re-cladding as the solution when leaks or decay are found.

However not all external framing decays. Not all framing gets wet, and dry framing does not need a cavity as it is already dry. If walls are dry, then whatever flashings are in place are working.

It is 100% possible to make a plaster clad house just as dry and safe as any other house –  without spending hundreds of thousands of dollars on re-cladding.

It’s time to be sensible about our houses and start making decisions that stack up with the facts.

Why Do Re-Cladding Companies and Councils Want Houses Re-Clad?

 The answer to the first part is obvious.  These companies, and the consultants who refer homeowners to them are set up to promote re-cladding.  They offer no alternatives, so re-cladding is recommended for any plaster-clad house with even a few minor issues.  We have seen dozens of instances where a full re-clad has only revealed a couple of small leaks.

The question of why the councils want you to reclad is a little more complex but maybe even more insidious.  On the surface, the building consent, inspection and Code of Compliance process makes total sense and ensures that the re-clad house has cavity construction, is weathertight and meets a reasonable durability standard.

Behind all of this though is the lingering liability councils may have for issuing consents and CCCs in the first place for buildings that are likely to leak and rot. That is one reason why reclads are so expensive – you are paying to fix all of those bad design, construction and material decisions that the council should never have passed in the first place

However, the opportunities now of holding the council to account are slim, so how do homeowners keep their houses safe while avoiding the re-clad?

A Mature Approach to Maintaining Plaster-Clad Houses

What if all of the leaks in the house could be located and the damage to the timber is only minor?  And what if the leaks could be stopped and any decay killed off? What if the timber could be treated so that it won’t rot in the future?  And what if there was a monitoring system in the house that gave an early warning if any new leaks started?

Would you want to spend money on a re-clad, when for a tiny fraction of the cost you could still have a safe, dry house?

What if there was proof for potential buyers that the house doesn’t leak, isn’t rotting and can be maintained indefinitely.

If all of these “ifs” were true, should there still be a ‘stigma’ attached to the house when it comes time to sell?

Wouldn’t this be a more mature way of approaching the issue rather than automatically assuming the house needs a re-clad?

Now we are not saying that you never need to re-clad because for some houses there just is no alternative, however this should be a last resort rather than the default approach.

Targeted Repairs and Treatment vs Re-Cladding

In 2005, the Moisture Detection Company patented the Mdu Moisture Detection Probes which have been installed discretely through the skirting boards in thousands of NZ homes.

Once the probes are in all locations where there may be a weathertightness risk, you have detailed information on any wet framing, any decay and what, if any timber treatment was used.

From that position of knowledge, you can make an informed decision about what to do next; do nothing, do targeted repairs and treatment, or go on for the full re-clad.

Targeted repairs and treatment have these goals:

  • Stop the leaks and modify defective details to manage or stop future leaks.
  • Ensure that timber that may be affected by current or future leaks is protected by adequate treatment.  If the timber is untreated then post-treat with RotStop.
  • Remove and replace decayed timber if it is affecting the structural integrity of the house – or just treat it and leave it.

That way buildings can be saved, remain healthy and liveable and for a lot less anxiety and costs. The Building Act does not mandate that no decay is allowed in a building. It does not even mandate no leaks. What it does mandates is that leaks are not to progress to cause structural problems, which is limited to load bearing, bracing and maintaining secure claddings and linings. External walls are often over engineered, with safety margins of 50% or more.  Leaving minor decay that has been treated in some walls has no effect on the structure and remains in full compliance with the Building Act.

Compare this to a re-clad where any timber within one metre of visibly stained wood is marked for replacement. This can mean expensive replacement even if the staining is due to the framing getting wet during construction and is still good, sound timber.

Moisture Detection Company Philosophy

  • Find and fix the leaks fast with Mdu Moisture Detection Probes.
  • Gather evidence before making any big decisions or spending big money.
  • Treat timber with RotStop to kill decay and protect against future leaks.
  • Monitor for new leaks by reading the Moisture Probes regularly.

Homeowners who adopt this process can maintain a typical plaster clad house and have a comprehensive package of documentation to prove to buyers that their house does not leak, and is safe to buy.