Thoughts on Roof Ventilators

Just wanted to know what people thought of roof space ventilators. Some examples
- http://www.edmonds.com.au/html/products ... _300mm.htm

- http://www.universaltileventilators.com.au/

My house is a double storey brick veneer home with charcoal coloured cement tiles. I am sure the temperature gets pretty high in the roof space during summer which in turn makes the indoor temperature high.

I am in the process of putting in additional insulation on top of the current insulfluf insulation which I am told has settled/compacted and only providing a R2.0 insulation rating at the most.

One installer said that roof ventilation will make a big difference and it should be the first thing I do. The other installer said it will make very little difference since there is already a slight breeze in the roof space due to the gaps in the cement tiles. I did notice that there is some air movement in the roof the last time I was up there, so I guess there is some truth in what the second guy was saying.

Do people have some experience, maybe from their own homes as to how much difference having roof ventilation will make?

Once the new insulation is installed, I will have around R5.0 worth of insulation in total. Is putting in ventilation still worthwhile?

Thanks,
rzk.

p.s Can someone please tell me if it is possible to install sarking in an existing house? I presume they will have to lift all the tiles, secure the sarking and then retile? Won't be cheap I guess...

See the recent thread: https://forum.homeone.com.au/viewtopic.php?t=9551

Chris

If your insulation is downgraded then I think your best to replace it first and see what it is like.
And then it will be useful in winter too.
Steve

I agree with Steve.
Also have a read through - http://forums.envirotalk.com.au/Eco-Housing-f52.html - there was some interesting discussion on roof ventillation.

There is a lot of controversy about this topic. From a scientific point of view it doesn't work unless you put a whole into your ceiling and open up your windows.

http://forums.envirotalk.com.au/Whirlyb ... t5419.html