# Forum Home Renovation General Odds & Sods  what ceiling insulation to use??

## wozzzzza

i have a top floor unit that has gyprock ceiling and corrugated iron on timber frame roof on standard slope and it gets damn hot. there is no insulation up there, what is a good type of insulation to use?? i dont know much about this stuff. can easily get up there and walk around inside the roof.
is this any good??  https://www.bunnings.com.au/earthwoo...of-18_p0810333

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## sol381

i use earthwool for most of my insulation. Very good stuff.   Not itchy at all. very good thermal quality. 4.0  will more than do the job. Just check your ceiling joist spacing.

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## wozzzzza

does insulation actually work? i'm still a bit sceptical about it all.

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## Whitey66

> does insulation actually work? i'm still a bit sceptical about it all.

   Of course it works, anything that inhibits the movement of air will insulate. 
If insulation didn't work, a lot of insulation companies would be out of business by now.
Another vote for earthwool from me, it's great stuff. When I insulated my shed walls I did it in a singlet and without gloves or goggles, I reckon you could sleep nude on it and remain itch free  :Biggrin: 
I have used this stuff https://www.bunnings.com.au/ametalin...ation_p0811234 on the roof of my new steel shed and it makes a huge difference.

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## wozzzzza

ok cool, may have to pay visit to bunnings get that insulation stuff.

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## phild01

Be sure it fits tight, no gaps. Is it a flat roof, what is access like.

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## Bros

> does insulation actually work? i'm still a bit sceptical about it all.

   We had steam pipes with 530deg steam surrounded with 200mm insulation clad with aluminium and you could put your hand on the cladding.  
i know this is not a house but the same principle applies. Insulation has advantages and disadvantages in that the building is slow to heat up and slow to cool down but overall the advantages are better than the disadvantages. 
As you are in Cairns you have to deal with the oppressive humidity.

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## wozzzzza

> Be sure it fits tight, no gaps. Is it a flat roof, what is access like.

  pretty easy access, you can stand up in there in centre. hipped style roof.  

> As you are in Cairns you have to deal with the oppressive humidity.

   dont remind me.

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## phild01

Also, care to keep insulation away from electrical cabling.

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## joynz

Read the Your Home guide which details the differing insulation requirements depending on climate.  Batts will slow the flow of heat inwards, but will also slow cooling down too. 
The links below detail insulation and the approaches in response to the Australian climate.  https://www.yourhome.gov.au/passive-design/insulation  https://www.yourhome.gov.au/passive-...design-climate 
Reflective foil reflects radiant heat from getting into the roof space in the first place. 
Consider a vent on the top floor to expel hot air - creating a ‘chimney effect’ or ‘stack ventilation’ effect where hot air is replaced by cooler air from on the lower floor - and can create a cooling breeze too.

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## John2b

> does insulation actually work? i'm still a bit sceptical about it all.

   It will make a HUGE difference. In Cairns without ceiling insulation you are living under a large thermal radiator! If you have a shallow sloped rood there will be a lot of heat gain. Steeper roofs get less hot. I would put reflective sarking under the iron with an air gap, i.e. staple it to the underside of the timbers (just avoid the Queensland experiment of stapling through electrical wires!) And then put a thermal blanket on the ceiling plasterboard as well, polyester or earthwool for preference over glass or mineral fibres for allergy reasons.

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## sol381

As most have said it makes a huge difference. Im renovating and have a small area about 1m2 that im using as a manhole , or access to the croof cavity. This is open. every time i walk under it its like an oven. Rest of the house is much cooler. Also the roof blanket i put in the carport also keeps temps down considerably.

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## wozzzzza

> Also the roof blanket i put in the carport also keeps temps down considerably.

   how does the roof blanket work in the car port? you got a picture of this?

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## sol381

This isnt mine but same thing. Just like any normal roof gets laid.

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## David.Elliott

So far I have managed to get all the insulation I have needed  from GT or FB as leftovers. Admittedly I have had to make a couple of trips here and there. I don't travel too far and I have saved about half of the retail cost, I'd estimate.

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## sol381

Its not cheap. Marketplace is good. At the moment any roof insulation is scarce. Bunnings dont have any.

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