[RJLink]

From today's New Zealand Herald

http://www.nzherald.co.nz/property/news/article.cfm?c_id=8&objectid=10592715

[Fern01]

It's not only immigrants. The day 'they' , the greenies, decided that there was to be no more treated timber used in the building of homes, was the start of a very slippery slope.

[caseysclan]

The article seems to be focussing mostly on some of the older homes as leaky homes. The truth is that its not just the older homes. I am a self employed sparky and have worked on a number of new build homes over here. I've been shocked at the construction of some of them. You get the ones that have polystyrene sheets or Hardiflex sheets that are skimmed over with 5mm skim of exterior plaster and then painted. Then there's the others that are sheets of plywood on the outside. For all the Poms ot there stick to the constructions that we are used to, brick or block. There are a lot of other materials that are still really good though. Get the house checked out by a Building Inspector and pay that bit more for a detailed report, its well worth it.
Cheers
Tom the Pom

[The Hodges]

A lot a useful comments there Tom. However, everyone should be aware that leaky homes are still being built and signed off today (a treated timber home will rot it will just take longer than untreated). A word of advice is get a pre-purchase report done by a reputable company.

See more information here (http://www.emigratenz.org/forum/showthread.php?t=12762&highlight=leaky+home).


It's not only immigrants. The day 'they' , the greenies, decided that there was to be no more treated timber used in the building of homes, was the start of a very slippery slope.

I am not sure if it was the greenies - I've seen no proof for this, but no treatment was allowed under certain conditions and it was the minimum. Houses could have been built with treated timber, but it seems that no-one was selling it.

[mylesdw]

I don't think it is anything to do with treated timber. It is about building methods and claddings that simply aren't waterproof. As mentioned above it is newer houses that suffer from it. We went through it all in the UK about 15 years ago except that it was known as 'timber framed houses' because we didn't know it was a syndrome :-)

[bobo]

I don't think it is anything to do with treated timber. It is about building methods and claddings that simply aren't waterproof. As mentioned above it is newer houses that suffer from it. We went through it all in the UK about 15 years ago except that it was known as 'timber framed houses' because we didn't know it was a syndrome :-)

I agree its more the construction than any other factor. Little or no sofits, no cavity, lack of weep holes etc. There are timber frame houses still standing in the UK that are older than pressure treated wood.

I don't really recall this as an issue in the UK 15 years ago (not doubting it).

[mylesdw]

Maybe a bit older, mid eighties I think they built a lot of timber framed houses using much the same method as many in NZ. The structure is in the timber and the bricks are just cladding or decoration, a single skin tied to the frame with clips. The design depended upon a plastic membrane between the bricks and the timber and builders being builders would damage the membrane leaving the frame open to penetrating damp. Once the frame has rotted the house is pretty much a write-off.

[The Hodges]

Yes, I remember the problem that the UK had (and mortgage companies would not lend on them and the construction companies had to fix them). I'm pretty sure that it was the 1980s...

Even parts of the States and Canada have had the same issues - well before NZ and as has been stated, the non-treatment of timber is not the problem in itself, although it doesn't help. Timber framed buildings have been around for a long time:

http://img01.beerintheevening.com/a8/a80340a8a6ac5288cdfb8480b93afb40.jpg

(one of my old locals :D)

And many of them do not have treated timber. The trouble is that there has been a systemic failure in the NZ construction industry, including the architects designing, councils processing, builders & sub-contractors building, councils inspecting etc. - which is why all these parties are named in proceedings, but as the Council is usually the last man standing, then have to pay.

If you are considering buying a house any where, my advice is to get it checked out by a reputable company.

[bobo]

Maybe a bit older, mid eighties I think they built a lot of timber framed houses using much the same method as many in NZ. The structure is in the timber and the bricks are just cladding or decoration, a single skin tied to the frame with clips. The design depended upon a plastic membrane between the bricks and the timber and builders being builders would damage the membrane leaving the frame open to penetrating damp. Once the frame has rotted the house is pretty much a write-off.

OK in 80's I was nowt but a bairn, so thats why I don't recall. I have never lived in any other type of house, the oldest being built in the 1950’s which predated plastic membranes or DCP.

IMHO there are big differences between how timber framed house are built in the UK and NZ with the main one being the lack of cavity and cavity vents, so when water penetrates it cannot get out and the wood is unable to dry off if it does get damp.

Because there is a cavity in modern UK TBF houses sections of the timber frame can be replaced, and in most case its localised problem due to a leaky roof etc. So it would be rare for a house to be a write-off due to a rotten timber frame.

[Super_BQ]

Perhaps if you take the profit motive out in residential property, houses in NZ would be built with the mind of lasting longer - instead of just lasting the general 7 year warranty period most home builders claim.

We had the highest bid at an auction for this home and the seller was expecting another $60K more on the price tag. So are people in NZ that stupid to pay so much for a 2nd hand house that the sellers could move out and build a new house for the same price? I do believe there's a sucker born everyday but people got to stop treating their home has a vehicle for investment and more of a house they truly enjoy to live in (without any profit motive). I think in NZ still the average house gets flipped every 6 years - not far off how long a brand new car will last.

BQ

[bob_the_engineer]

My house is 70 years old. Its wooden framed with a stucco coat (plaster). The timber was probably treated with something quite noxious too.

It doesn’t leak, the timber is in excellent order, I know this because I’ve pulled out loads of the plasterboard to insulate it. It’s a solid house.

My philosophy (probably much like the builders that used to build houses), is keep the water out, rather than give it ventilation to dry!

Why is 70 year old plaster completely water proof, while recent plaster seems to leak like a sieve!

Ok the house does have wide eves, but I can’t imagine that’s the only reason why it’s not damp, as I’ve said I’ve been inside the walls, at the height of winter too, and they are completely dry…

Bob

[Super_BQ]

Why is 70 year old plaster completely water proof, while recent plaster seems to leak like a sieve!

The issue with leaky plastered houses in NZ and your plastered home 70s years ago, is more to do in differences in wall construction. The problem arises because houses in NZ are built to 'breath' (that is they rely on the gaps and draftyness in the wall to rid condensation to the outside). Then the idea came along to use polystyrene cladding with the plaster finish over it. What they forgot was houses in NZ were originally (err.. intentionally) designed to breath and not to be air tight. Once the plaster finish has been breached, then the rain water flows in and voila - disaster.

There's nothing wrong with plaster of polystyrene homes IF the homes have proper mechanical ventilation. For such houses, they are built air tight and fresh air is supplied mechanically via the furnace ducting and or an HRV/ERV system. Both of which are rarely found in NZ homes. As a matter of interest, I do not believe installations of such HRV/DVS systems in NZ homes are suitable because their efficiency is compromised due to "breathable home construction".

For the newer building companies continuing to build with plaster, they too have rid the use of polystyrene and now use low quality bricks. The plaster goes over them and there's nothing to rot even if the plaster finish is breached.

Looking at the wall construction is 1 aspect. More importantly we must look at the type of foundation. Your 70 year old home would of been built with hollow cavity flooring whereas modern homes are on concrete foundation. The key difference is the wood floors allow for air movement to rid any condensation. With concrete, well moisture can soak into the concrete and the timber framing can suck that water up.

So what we have is a combination of modern building techniques causing all sorts of problems.

[bob_the_engineer]

The issue with leaky plastered houses in NZ and your plastered home 70s years ago, is more to do in differences in wall construction. The problem arises because houses in NZ are built to 'breath' (that is they rely on the gaps and draftyness in the wall to rid condensation to the outside). Then the idea came along to use polystyrene cladding with the plaster finish over it. What they forgot was houses in NZ were originally (err.. intentionally) designed to breath and not to be air tight. Once the plaster finish has been breached, then the rain water flows in and voila - disaster.

There's nothing wrong with plaster of polystyrene homes IF the homes have proper mechanical ventilation. For such houses, they are built air tight and fresh air is supplied mechanically via the furnace ducting and or an HRV/ERV system. Both of which are rarely found in NZ homes. As a matter of interest, I do not believe installations of such HRV/DVS systems in NZ homes are suitable because their efficiency is compromised due to "breathable home construction".

For the newer building companies continuing to build with plaster, they too have rid the use of polystyrene and now use low quality bricks. The plaster goes over them and there's nothing to rot even if the plaster finish is breached.

Looking at the wall construction is 1 aspect. More importantly we must look at the type of foundation. Your 70 year old home would of been built with hollow cavity flooring whereas modern homes are on concrete foundation. The key difference is the wood floors allow for air movement to rid any condensation. With concrete, well moisture can soak into the concrete and the timber framing can suck that water up.

So what we have is a combination of modern building techniques causing all sorts of problems.

That’s interesting. My house is on a concrete pile with a solid concrete exo-foundation.

The builders paper is quite an interesting material, it’s a fibrous tar paper that has a conical pierce. You can pour water on one side (the inside face) and it quickly passes through. But if you pour water on the outside face it pools.

I have to say I do understand what your saying, despite the concrete perimeter of my foundation, the floors are wooden and there is a good airflow under the house because it is stood on a concrete pile rather than a sold concrete base. That will give plenty of room for water to disperse and evaporate.


Bob

[John Z]

............

My philosophy (probably much like the builders that used to build houses), is keep the water out, rather than give it ventilation to dry!

.......

I agree to keep water out, but proper ventilation has more than one function;

think of material gasses, condensation (inside out), dry rott.