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Roofing – Replace Tiles with Colourbond

By PB_Lyneham 9 September 2014 28

I am looking at replacing our tired and cracking tiled roof with Colourbond. I have recieved two quotes which are reasonably comparable.

One quote came from a small business: Simply Guttering and Roofing.

The second came from WR Engineering.

I am hoping people can let me know if anyone has either positive or negative comments about either of these two companies based onwork tyhey have done in the last year or two.

Many Thanks

What’s Your opinion?


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28 Responses to
Roofing – Replace Tiles with Colourbond
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rommeldog56 4:44 pm 27 Feb 15

I have to have may roof tiles replaced (with used ones for matching) + ridgecapping re bedded/re pointed (flexipoint). Tiler recommended metal flashings to gable ends colour coded to facia colour. 18.5 sq house and separate brick double garage.

But have been ball park quoted $20+K to replace tiles with colorbond. Would like to do that but cost is prohibitive Im afraid.

So, does anyone have any recent positive experience with roof tilers for this work + how has the job you got done 5+ years ago standing up ? there seems to be a common complaint in CBR that the rebedding/repointing may only last 5 years or so ?

Not interested in painted roofs.

I dont mind paying fair money for a good, long lasting job.

All contributions greatly appreciated.

davo101 9:44 am 15 Sep 14

Russ said :

davo101 said :

No, I think you were correct. It sounds like they were thinking of Kirchhoff’s Law but forgetting that a house roof is not a gray body. While a white roof does have a much lower absorptivity than a black roof for the incoming short-wave radiation, for the outgoing long-wave radiation the emissivity of a painted surface is almost independent of its colour.

I don’t believe emissivity of the roof surface is that relevant to a house’s thermal performance as the roofspace typically isn’t designed to hold in heat. Absorptivity would govern how much heat is gained in the roofspace in both summer and winter, and so the principle would still apply that a dark roof is better in winter as it will absorb more heat, leading to a hotter roofspace reducing the heat lost through the ceiling. Similarly a white roof will absorb less heat, leading to a relatively cooler roofspace in summer.

That said, most would regard reducing the roofspace heat in summer as being the greater priority, in which case you’d typically run foil-backed fibreglass blanket under the roofing, combining the benefit of the bulk insulation of the fibreglass with the low emissivity of the foil. Only downside of that is the roof doesn’t sound as nice when it rains due to the damping effect of the blanket.

Yeap, that’s what I said. Thanks for the executive summary 🙂

Maya123 said :

So does that mean that in summer a light roof is better to keep a house cooler, but in winter it doesn’t matter what colour the roof is to keep the house warm? If that is the case the pale roof is the better suggestion, because at least in hot weather it has some effect, while in winter the colour is irrelevant.

I haven’t seen any calculations specifically for Australia, but in general the forgone solar gain in Winter is not that great so you are better off with a light coloured roof, as the effect on cooling loads in Summer is significant.

dungfungus 11:27 am 13 Sep 14

HenryBG said :

davo101 said :

No, I think you were correct. It sounds like they were thinking of Kirchhoff’s Law but forgetting that a house roof is not a gray body. While a white roof does have a much lower absorptivity than a black roof for the incoming short-wave radiation, for the outgoing long-wave radiation the emissivity of a painted surface is almost independent of its colour.

Careful, you’re starting to sound a bit complicated and scienc-ey.

The peasants will be out with their pitchforks and torches if you keep that up.

Torches? Only a few days ago you were mentioning fire sticks. Are you a closet incendiarist?

Russ 10:30 am 13 Sep 14

davo101 said :

No, I think you were correct. It sounds like they were thinking of Kirchhoff’s Law but forgetting that a house roof is not a gray body. While a white roof does have a much lower absorptivity than a black roof for the incoming short-wave radiation, for the outgoing long-wave radiation the emissivity of a painted surface is almost independent of its colour.

I don’t believe emissivity of the roof surface is that relevant to a house’s thermal performance as the roofspace typically isn’t designed to hold in heat. Absorptivity would govern how much heat is gained in the roofspace in both summer and winter, and so the principle would still apply that a dark roof is better in winter as it will absorb more heat, leading to a hotter roofspace reducing the heat lost through the ceiling. Similarly a white roof will absorb less heat, leading to a relatively cooler roofspace in summer.

That said, most would regard reducing the roofspace heat in summer as being the greater priority, in which case you’d typically run foil-backed fibreglass blanket under the roofing, combining the benefit of the bulk insulation of the fibreglass with the low emissivity of the foil. Only downside of that is the roof doesn’t sound as nice when it rains due to the damping effect of the blanket.

HenryBG 8:11 pm 12 Sep 14

davo101 said :

No, I think you were correct. It sounds like they were thinking of Kirchhoff’s Law but forgetting that a house roof is not a gray body. While a white roof does have a much lower absorptivity than a black roof for the incoming short-wave radiation, for the outgoing long-wave radiation the emissivity of a painted surface is almost independent of its colour.

Careful, you’re starting to sound a bit complicated and scienc-ey.

The peasants will be out with their pitchforks and torches if you keep that up.

Maya123 6:41 pm 12 Sep 14

davo101 said :

Maya123 said :

Paint it a pale colour though if you want to save on heating and cooling costs. Don’t ask me the physics of this, but I have had a couple of people with relevant science backgrounds independently attempt to explain this to me. The pale roof in summer is easy to visualise assisting to keep the house cooler, but a pale roof in winter also assists to keep the house warmer in winter. I had thought a darker roof would be better in winter, but I was wrong.

No, I think you were correct. It sounds like they were thinking of Kirchhoff’s Law but forgetting that a house roof is not a gray body. While a white roof does have a much lower absorptivity than a black roof for the incoming short-wave radiation, for the outgoing long-wave radiation the emissivity of a painted surface is almost independent of its colour.

So does that mean that in summer a light roof is better to keep a house cooler, but in winter it doesn’t matter what colour the roof is to keep the house warm? If that is the case the pale roof is the better suggestion, because at least in hot weather it has some effect, while in winter the colour is irrelevant.

davo101 12:07 pm 12 Sep 14

Maya123 said :

Paint it a pale colour though if you want to save on heating and cooling costs. Don’t ask me the physics of this, but I have had a couple of people with relevant science backgrounds independently attempt to explain this to me. The pale roof in summer is easy to visualise assisting to keep the house cooler, but a pale roof in winter also assists to keep the house warmer in winter. I had thought a darker roof would be better in winter, but I was wrong.

No, I think you were correct. It sounds like they were thinking of Kirchhoff’s Law but forgetting that a house roof is not a gray body. While a white roof does have a much lower absorptivity than a black roof for the incoming short-wave radiation, for the outgoing long-wave radiation the emissivity of a painted surface is almost independent of its colour.

dungfungus 8:14 am 12 Sep 14

Canberroid said :

dungfungus said :

Maya123 said :

dungfungus said :

switch said :

dungfungus said :

Make sure you get at least a 30 year warranty on the product.
I have seen a couple of 20 year old Colourbond roofs lose their colour in my suburb. At least one has been replaced.

Must be climate change.

Personally, apart from obviously fixing tiles that are broken and leaking water into the roof space, I’d save my money and leave it alone.

Climate change is harmless – it’s more likely to be electrolysis caused by using the wrong fixing screws.
Tiles and ridge caps generally need pointing every 20 years and you can even get a grotty tiled roof pressure cleaned and painted (looks better than new).

Paint it a pale colour though if you want to save on heating and cooling costs. Don’t ask me the physics of this, but I have had a couple of people with relevant science backgrounds independently attempt to explain this to me. The pale roof in summer is easy to visualise assisting to keep the house cooler, but a pale roof in winter also assists to keep the house warmer in winter. I had thought a darker roof would be better in winter, but I was wrong.

I am sure HenryBG will be able to explain this simply by supplying dozens of links and writing a few short tomes.

And I’m sure you’ll be able to explain that he’s wrong because you don’t understand the information he provided and that you were once in a warm house with a dark roof during winter.

If there is a simple explanation forthcoming from the sage then I will consider it and if I agree I will confirm that.

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