LEAKY HOMES & REASONS

[dinosaur]

Just like to add my ten cents worth here.

One aspect the powers that be have not addressed is internal moisture. The cladding can be as water tight as a submarine, but unless you have systems to remove internal moisture, you will have moisture and rotting in external walls.

As Duncan mentoned, they didn't have a problem in the 1970 because houses still breathed then, although we have to insulate now. No building paper was used behind bricks or timber weatherboards, except shiplap back then. Holes were drilled for ventilation so that dry roof space air could circulate down through the walls. Now it is mandatory to seal the roof space off from the wall cavity. To make it worse, people now days tend to leave houses shut up during the day because they are working and at night for security, so that internal moisture just hangs around waiting for a cold surface to condensate on which are in the external walls.

That old black buiding paper which was absorbant has mainly been replaced by non-absorbant synthetic wraps which are basically plastic with a few holes punched in it and they call it breathable. They say they have been tested. Well have you seen what happens to carrots when you leave them in those plastic bags with holes in? Yes, they rot.

There are a couple of brands of wraps that are absorbant but I see mainly the cheaper wraps being used.

With no ventlation in the walls I believe we are sitting on a time bomb as the new Building Act has moved to make walls even more airtight.

In Canada, where our powers that be have looked for a solution, they heat the entire house 24/7 over winter, so interiors tend to be dryer than here in NZ. Here we are told only to heat the room we are in. Plus people still use unvented LPG heaters. You then can't use Canadian systems here and expect to get the same results.

But don't listen to me, I'm just an old dinosaur with 35 years experience in the building industry.

[airedale]

I know a builder in Auckland. He has a job with one of the companies that have a contract to [try and ] deal with " leaky homes". The house that he was working on a few months ago had actually won the Master Builders Home of The Year two years ago. It still leaked.

[minimoke]

The house that he was working on a few months ago had actually won the Master Builders Home of The Year two years ago. It still leaked.

There must be some mistake? Dunc started this thread in 2005 - and leaky homes had been around before then. The master builders home was probably built in the last four years - hopefully the tax payer isn't stumping up to repair this one!

[airedale]

That is the point, Minimoke, "leaky homes" have been around since building standards were changed for the worse, and they are still being built.