Roof color in the thermal equation

Good Job Perry!

I have to agree - that white/pale roof on that house sort of looks a bit wrong. Like it's covered in snow or something. I'm sure it could be done tastefully (and apologies to the owner of the house) but I'm not sure that the darker bricks and trims contrast well with the stark white.

Ray.

Appearance is a higher priority than efficiency in my book, but I am concerned about a dark grey colorbond roof fading significantly.

Does anyone have experience in this over say 10 years or so? Or have colouring technologies changed recently enough that older roofs are no longer an indication of fading.

....now I'm going to be petrified to post any further pics of our house

though it looks like nothing like that one...!

That picture is sooo bad, I'm considering removing it from my server!

Perry

This pic isn't the best, but do you reckon it's the darkest grey that has been used here?
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Sorry Parker, try again.

parker - looks like Ironstone to me - it can look quite dark in the shade, but quite light in full sun.

Roof colour definately makes a difference in the ceiling space temperature and ventilators do work - but you do not always need much ventilation.

Main issue - - You need to make sure it is the best option for your area.

In Sweden they all love to buy black cars - guess why - (So they can find them in the snow - Just kidding so they get warmer quicker -
And when I lived in the tropics - White cars was our colour of choice

Re roofs - In the tropics too much ventilation will let lots of moist air in - and in colder climes not enough venting can hold moisture in - so it's a design balance.

Re roof temps there is an intersting article here for Alice Springs - An extreme environment.

Roof colour and ventilation

In central Australia, light coloured roofs reflect far more heat than dark roofs.
One monitored roof in Alice Springs of white painted corrugated iron was
45°C underneath on a 38°C day when neighbouring dark green, maroon and unpainted grey sheets were 70°C1. Rooms were up to 4°C cooler even though roof batts and foil were used.

Ventilate the roof space to release trapped summer heat. Use perforated eaves and ‘whirly gig’ ventilators to optimise air flow.

Monitoring of a fully vented local roof showed it was only 1°C above ambient air temperature in summer.

http://www.nt.gov.au/nreta/environment/greenhouse/pdf/suitablehousingca.pdf

So work out what's best for you area is the key.
If your insulation is getting very hot - then the main area of heat transfer will be through the actual ceiling timbers to gryprock connection - not the insulation. and the reverse in winter.
Let alone the windows and door gaps.
Steve

Do whirlybirds run on electricity? I was under the impression that they turn according to air pressure... something like how we have high-low pressure wind movement on the weathermaps... dumb question