Need input on a roofing quote

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wellygary

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#3471863 19-Mar-2026 21:16

According to a quick google, the difference between treated and untreated ply is about $25/2.4*1.2m panel or ~$10 sq m.. so it should add about $1500 to your price....

https://www.placemakers.co.nz/online/timber-plywood/plywood/c/RWAF1?q=%3ASort+By%3Acategory%3ARAF01W1

mattwnz

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#3471864 19-Mar-2026 21:28

We have plywood supporting the metal trays, pretty sure treated and 22mm, and I don’t think it cuts down on noise very much, and that wasn’t the reason it was installed

sommot

13 posts

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#3471867 19-Mar-2026 21:33

mattwnz:

We have plywood supporting the metal trays, pretty sure treated and 22mm, and I don’t think it cuts down on noise very much, and that wasn’t the reason it was installed

How is the noise during heavy rain?

mattwnz

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#3471871 19-Mar-2026 22:06

Can still hear it. Possible because the plywood is in contact with the metal. R 5 insulation as well so don’t know if that helps more.

elpenguino

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#3471874 19-Mar-2026 22:26

sommot:

So I'm getting a new roof put in and I've gone for a Colorsteel metal roof but I've asked them to add a layer of plywood sheathing as well as the normal underlayment. They quoted the install of 15mm untreated T&G plywood sarking at ~$8000. The entire roof is ~150m2 and will cost a bit over $30k (inc GST) including the plywood. Does this look about right? I really have nothing to else to go on so any input appreciated.

I recently got replaced a roof of ~100m2, also coloursteel, and it cost 22k. It looks like you're in the right ball park.

Don't forget any little porches or other odds and sods you may have.

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sommot

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#3473278 24-Mar-2026 18:25

Update: I have a quote that is using Colorcote Magnaflow instead of Colorsteel Maxxam. We've decided on Gull Grey for the colour but that was with Colorsteel samples. Colorcote also has a Gull Grey but I'm not sure if they're the same. I'm also unsure whether or not Colorcote is as good as Colorsteel in terms of performance which is what everyone seems to use. Anyone know if I should go with one or the other?

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mattwnz

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#3473300 24-Mar-2026 20:24

Personally I would go colorsteel as it is long term proven product. Don't know enough about the alternative brand. My issue though with it is that it seems very suspectable to lichen growth over time (4+ years), over a plain zinculume roof.

sommot

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#3473301 24-Mar-2026 20:36

mattwnz:

Personally I would go colorsteel as it is long term proven product. Don't know enough about the alternative brand. My issue though with it is that it seems very suspectable to lichen growth over time (4+ years), over a plain zinculume roof.

You mean the Colorsteel or Colorcote more susceptible? But I agree with you on the Colorsteel being more widely used. I've not heard of Colorcote until the quote came in.

mattwnz

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#3473303 24-Mar-2026 20:46

Colorsteel seems prone to lichen. But that may just apply to any painted coating on steel

bebek

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#3473304 24-Mar-2026 20:55

Colorsteel made by New Zealand Steel, the only steel manufacture in New Zealand. Factory located at Glenbrook.

Colorcote is part of the Fletcher Building group. Don't know where they got the roof from. My guess is either it is imported or made by NZ Steel.

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