suddenly non GIB boards are approved for use

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#2948360 30-Jul-2022 15:57

Handsomedan:
old3eyes:

Yes and all that involves extra money to be paid to the council for their rubber stamp to change from Gib to something else regardless where it is certified.

That's the reason for many things...slightest change requires more permitting and therefore more money. Ludicrous.

It’s not driven by a desire for more fees, it’s about avoiding risk.

The leaky building fiasco got a lot of councils sued for allowing certification of products and construction techniques that didn’t work. When that happens they become risk adverse.

tweake

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#2948362 30-Jul-2022 16:16

Handle9:

It’s not driven by a desire for more fees, it’s about avoiding risk.

The leaky building fiasco got a lot of councils sued for allowing certification of products and construction techniques that didn’t work. When that happens they become risk adverse.

the knock on effect of that is sticking to pre spec'ed solutions. anything thats "different" takes longer to get approved, so they spec gib so it doesn't get held up and cost more.

shk292

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#2948449 30-Jul-2022 19:26

It's about time the monopoly was broken. Using a brand name instead of a generic term is never a good sign - Gib, Batts, etc. Other countries seem to manage OK without Gib

mattwnz

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#2948455 30-Jul-2022 20:03

The big complication in NZ comes because a NZ is a high risk earthquake country and plasterboard is used for bracing. If you can’t use plasterboard for this purpose in all areas, an engineer maybe required and that could add a lot to the cost. I think gib are the only ones who have special plasterboard bracing software that is easy and straightforward to use.

insane

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#2948485 31-Jul-2022 00:02

shk292:
It's about time the monopoly was broken. Using a brand name instead of a generic term is never a good sign - Gib, Batts, etc. Other countries seem to manage OK without Gib

Let's play devil's advocate for a moment. Assuming an open playing field existed, the GIB competitive advantage was product range, great support for architects/engineers, local production leading to acceptable product costs, and all around easy to deal with and reliable supplier able to meet demand.

In the case of overseas players being unable to complete in market, then arguably they needed to invest to build local capacity.

I guess given the greed we see in all directions of life now, it's not surprising to hear that anti-competitive underhanded tricks were used to snuff out competition - and for that reason I have little sympathy for them.

Hopefully this is the catalyst we need to trigger this across all materials.

shk292

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#2948541 31-Jul-2022 11:41

insane Let's play devil's advocate for a moment. Assuming an open playing field existed, the GIB competitive advantage was product range, great support for architects/engineers, local production leading to acceptable product costs, and all around easy to deal with and reliable supplier able to meet demand.

In the case of overseas players being unable to complete in market, then arguably they needed to invest to build local capacity.

I guess given the greed we see in all directions of life now, it's not surprising to hear that anti-competitive underhanded tricks were used to snuff out competition - and for that reason I have little sympathy for them.

Hopefully this is the catalyst we need to trigger this across all materials.

I'm sure it was open competition and a free market originally. But I've been living here for over 15 years (this time around) and have never heard people refer to "plasterboard" or "dry-lining", only "Gib". Similarly, I remember being amazed/puzzled at school in the 70s as a new immigrant when people talked of having "bats" (that's how I heard it) in their attic for insulation. I was trying to imagine how you'd persuade enough bats into the attic to make a difference, and the mess they would make.

The effective monopoly, and the sharp practice of builders paying non-discounted prices to wholesalers and passing these on with margin to customers, while at the same time receiving hefty backhanders in the form of bonuses etc, goes a long way to explaining why NZ building prices are so high.

I agree - let's hope this is a catalyst for change

MikeAqua

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#2949104 1-Aug-2022 13:02

Why don't we use some sort of rigid panel on the exterior side of the framing. It could serve as bracing and a cavity barrier?

If the US they seem to use OSB for this, including in California, which is as quaky as NZ.

Mike

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wellygary

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#2949163 1-Aug-2022 13:37

MikeAqua:

Why don't we use some sort of rigid panel on the exterior side of the framing. It could serve as bracing and a cavity barrier?

If the US they seem to use OSB for this, including in California, which is as quaky as NZ.

You can,

Google "Rigid air barrier" there are numerous approved solutions that allow the use of solid exterior sheet as part of the construction process...

But NZ doesn't operate a prescriptive regime, you are still free to use a flexible barrier method ( house wrap) and then use approved plasterboard that is certified for bracing...

Its a horses for courses regime and its usually the cheap option that becomes dominant...

tweake

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#2949319 1-Aug-2022 16:18

MikeAqua:

Why don't we use some sort of rigid panel on the exterior side of the framing. It could serve as bracing and a cavity barrier?

If the US they seem to use OSB for this, including in California, which is as quaky as NZ.

as mentioned cost is a big factor. it does get used a bit in high wind loading areas. but kiwis really don't care so much about insulation (wind washing of insulation), or air tightness, or sound proofing.

however some builders do use RAB or sheathing because it can cut down on labor costs. with house wrap, the house is not considered closed in until all cladding is done. so they end up waiting on the cladding crew to do their work before they can do anything else. where as with RAB/sheathing once its on the building is considered closed in and all other work can continue while the cladding crew are still doing the cladding. hence it can be a big time saver, as well as better air tightness, better insulation, better soundproofing, and a stronger house which may not need structural gib.

MikeAqua

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#2949383 1-Aug-2022 16:39

tweake:

as mentioned cost is a big factor. it does get used a bit in high wind loading areas. but kiwis really don't care so much about insulation (wind washing of insulation), or air tightness, or sound proofing.

however some builders do use RAB or sheathing because it can cut down on labor costs. with house wrap, the house is not considered closed in until all cladding is done. so they end up waiting on the cladding crew to do their work before they can do anything else. where as with RAB/sheathing once its on the building is considered closed in and all other work can continue while the cladding crew are still doing the cladding. hence it can be a big time saver, as well as better air tightness, better insulation, better soundproofing, and a stronger house which may not need structural gib.

We're currently designing a house. On hold until sanity returns to the building market (we own the land and it ain't going anywhere).

We'll be going with rigid panel on the outside of the framing. Add in140mm framing and block cladding and it's going to be very solid and quiet. Some of the rooms will have 18mm blue gum interior lining too.

Mike

tweake

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#2949398 1-Aug-2022 17:15

MikeAqua:

We're currently designing a house. On hold until sanity returns to the building market (we own the land and it ain't going anywhere).

We'll be going with rigid panel on the outside of the framing. Add in140mm framing and block cladding and it's going to be very solid and quiet. Some of the rooms will have 18mm blue gum interior lining too.

blue gum, o thats nice 😍

with RAB consider going the whole hog and making it fully air tight. its not as hard as many make it out to be. i'll find some links about that.

insulation wise, unless its double story, its worth mentioning 4" wall with 2" external insulation. trade a bit of building strength for better insulation and increased durability compared to 6" walls.

tweake

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#2949404 1-Aug-2022 17:34

check out https://youtu.be/omZ3U-Iixds

if a musician and actress can make their first house they build 10 times more air tight than nz passive house standard, i'm sure you can. (i think they get it even more air tight in the end but i can't find the video)

https://youtu.be/_lqr8R2i5Vo exterior insulation.

mattwnz

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#2949467 1-Aug-2022 18:43

MikeAqua:
Why don't we use some sort of rigid panel on the exterior side of the framing. It could serve as bracing and a cavity barrier?

If the US they seem to use OSB for this, including in California, which is as quaky as NZ.

Gib make one and it is purple in colour. Not sure how common RAB are used in bracing calculations, as some are relatively thin, and used more as an air barrier in very high wind zones. But I understand they can be used for bracing in external walls. Often you see plywood installed with a lay of building wrap over the top

MikeAqua

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#2949619 2-Aug-2022 09:40

tweake:

blue gum, o thats nice 😍

with RAB consider going the whole hog and making it fully air tight. its not as hard as many make it out to be. i'll find some links about that.

insulation wise, unless its double story, its worth mentioning 4" wall with 2" external insulation. trade a bit of building strength for better insulation and increased durability compared to 6" walls.

The gums are growing on the property and will be milled just down the road. I think they'll look good. They're very straight with enough small branches to ensure a bit of figure.

I'll look into the sealing up. I'll be doing a lot of the tedious parts of the building, so we can afford to do labour intensive stuff like that.

I need the wall depth for the format of windows that I want.

I'm note sure about insulating with foam outside the cladding. We're leaning towards a large stone block type cladding.

Mike

evilengineer

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#2949653 2-Aug-2022 11:17

mattwnz:Gib make one and it is purple in colour. Not sure how common RAB are used in bracing calculations, as some are relatively thin, and used more as an air barrier in very high wind zones. But I understand they can be used for bracing in external walls. Often you see plywood installed with a lay of building wrap over the top

RAB Board (by James Hardie) comes in 6mm and 9mm thick and they have published bracing ratings for both.

There's also "Ecoply Barrier" by CHH (plywood) and IBS Rigid Rap (OSB) available on the market with BRANZ/Codemark bracing ratings as well.

Also, fairly certain you don't need an extra building wrap on top of these Ply/OSB products as long as the sheet joints are properly taped as per the installation manuals.

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