Roof insulation.

But doesn't it keep the heat trapped inside? Cos heat is sure to make its way into the home during the day through the windows and walls.
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Go into the roof in on a summer day. How much hotter is it than the rest of the house?
Heat rises, but most of the heat is from the sun-> roof, not rooms to ceiling.

Think of it this way -

The sun is above.
The roof is above.

Most roofs are made from metal or tile, those absorb a lot of heat.

The thing thats going to get heated the most is the roof area.
Insulating that will prevent a lot of the heat coming in from that area.

Heat does rise, but most of the heat in the home is generated from the roof in summer, not the rest of the house.



Another solution would be to paint the roof white, as this is reflective.
Or, mount solar panels, and kill 2 birds with one stone - my roof is partially covered by solar panels, this helps, as they're mounted above the roof, and keep the underlying area cool, plus generate electricity.
Its a little more expensive than roof insulation though ;)
And mount those roof mounted twirly extraction fans, as those help too, drawing air through.


US Gov PDF which describes all this in more detail - http://www.nrel.gov/docs/legosti/old/15771.pdf
 
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3Gee said:
Have you noticed a big difference in temperature with the current heat wave?
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Oh yes it makes a huge difference, it was money well spent.
My aircon units have seen only four days of intermittent use since this heatwave started, so we are saving cash too.

It was 42C here in Durbanville about two weeks ago and the temp inside on the Southern side of the house was 29.5C.
Not pleasant, but still agreeable.

On more normal summer days, the temperature inside is between 8 to 10C lower than outside.

The north-facing rooms however is noticeably hotter due to direct heat transfer through the windows and I suppose that double-glazed windows will be the best way to fix that problem.


It is worth repeating what other posters have said before:
Do not even think about it, just do it.
 
air said:
thanks lsheed_cn, would one need to turn the twirly fans 'off' in winter?
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I was leaning towards yes, but a cursory google says no, as its needed to reduce moisture/ humidity up there.
Again, we don't live in the roof, we live in the bits under it, so making sure those room shaped bits we live in are nicely insulated is the key.
 
Does it not matter what type of roof you have?

I am looking for the best insulation for my Bathroom, it has a sheet metal roof and it is quite warm where I live. 40 - 42 is normal summer temperature where I live.
 
Inevitability said:
indicative pricing: R1100 upwards
http://tepla.co.za/domestic-roof-ventilation

This looks like an interesting alternative, and should be alot cheaper
http://www.monier.co.za/fileadmin/bu-files/za/Downloads/6711_Dry_Ridge_Brochure_print_.pdf
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Would these extractor fans actually work?

Is it possible to let it work off a small solar panel or does it not draw a lot of electricity?

I have insulation in my roof but the house is still a small oven inside so was wondering if this will make a noticeable difference.
 
The_Mowgs said:
Would these extractor fans actually work?

Is it possible to let it work off a small solar panel or does it not draw a lot of electricity?

I have insulation in my roof but the house is still a small oven inside so was wondering if this will make a noticeable difference.
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They don't need power. Work from the wind. Hardly any wind here at the moment and it is spinning at a decent speed. Think I need to get a second one, as only one is not coping with the size of our roof.
 
The_Mowgs said:
Would these extractor fans actually work?
Is it possible to let it work off a small solar panel or does it not draw a lot of electricity?
I have insulation in my roof but the house is still a small oven inside so was wondering if this will make a noticeable difference.
Click to expand...
I don't see them much in homes, but the theory is sound... hot air rises, and we want that s**t vented, so...
"Let it goooooooo, let it goooooooo", and the heat won't bother you anymore :)
As for the solar panel... Maybe I'm an idiot, but I thought those fans didn't use electricity.

[video=youtube;moSFlvxnbgk]https://www.youtube.com/watch?v=moSFlvxnbgk&t=59[/video]
 
ABCpt said:
They don't need power. Work from the wind. Hardly any wind here at the moment and it is spinning at a decent speed. Think I need to get a second one, as only one is not coping with the size of our roof.
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What is the size of your roof or house if you dont mind me asking and also, did you notice some difference since installing one.

Lastly, which model did you install?
Inevitability said:
I don't see them much in homes, but the theory is sound... hot air rises, and we want that s**t vented, so...
"Let it goooooooo, let it goooooooo", and the heat won't bother you anymore :)
As for the solar panel... Maybe I'm an idiot, but I thought those fans didn't use electricity.

[video=youtube;moSFlvxnbgk]https://www.youtube.com/watch?v=moSFlvxnbgk&t=59[/video]
Click to expand...
Yeah should probably read before I ask questions next time as I saw afterwards it works with the wind.
 
The_Mowgs said:
What is the size of your roof or house if you dont mind me asking and also, did you notice some difference since installing one.

Lastly, which model did you install?

Yeah should probably read before I ask questions next time as I saw afterwards it works with the wind.
Click to expand...

It's hard to say. House is about 210m2 and the highest point in the ceiling is probably about 2.5m. It does make a difference if you are in the ceiling, so it must have an influence on the temp in the house.
It is the supevent.
http://www.bautecappliances.co.za/pSV250/Supavent-Turbine-Ventilator-250mm.aspx
and it was all star roofing who did it for me. 4 Years ago they had the best price. Just found the order, which was placed on 18 Jan 2012 and they installed on the 23 Jan 2012.
http://allstarroofing.co.za/
 
ABCpt said:
It's hard to say. House is about 210m2 and the highest point in the ceiling is probably about 2.5m. It does make a difference if you are in the ceiling, so it must have an influence on the temp in the house.
It is the supevent.
http://www.bautecappliances.co.za/pSV250/Supavent-Turbine-Ventilator-250mm.aspx
and it was all star roofing who did it for me. 4 Years ago they had the best price. Just found the order, which was placed on 18 Jan 2012 and they installed on the 23 Jan 2012.
http://allstarroofing.co.za/
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Thanks very much. Will do some more reading
 
The_Mowgs said:
Would these extractor fans actually work?

Is it possible to let it work off a small solar panel or does it not draw a lot of electricity?

I have insulation in my roof but the house is still a small oven inside so was wondering if this will make a noticeable difference.
Click to expand...

I was cooking in my place yesterday, but it seems that the heat was such that it baked the walls to a point where the interior walls were hot still at night. I dont think anything is gonna help with that other than an aircon.
 
calypso said:
I was cooking in my place yesterday, but it seems that the heat was such that it baked the walls to a point where the interior walls were hot still at night. I dont think anything is gonna help with that other than an aircon.
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I have a aircon in the lounge but if theres another solution that might also make a difference, even a little difference, I would consider it.
 
I have seen this. My only problem is that it's only available in white. Not sure if you can paint over it in another colour
 
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