aluminum foil as insulation

[tony123]

We've just settled a house which is approx 40 yo. The house does have insulation but we estimate the fibre batts are about 20 yrs old.

Since we don't have enough money to replace the batts, we were thinking of covering the batts with domestic aluminum foil to create a radiant barrier.<o>

</o><o></o>Will this have much difference??<o></o><o></o>
Are there any other alternatives?


tony

[Pulse]

Why not just use the sarking made for the purpose, a lot easier to put in!

Cheer
Pulse

[tony123]

Why not just use the sarking made for the purpose, a lot easier to put in!

Cheer
Pulse

Should I just cut up the Sarking and place over the existing insulation ??

tony

[silentC]

To be honest, I doubt you'll get a noticable difference by putting in sarking. You might also find that some low rating batts are cheaper and probably more effective if you install them over the old ones.

However, I know of people who have had good results from putting a rotary vent in the roof. That would possibly be cheaper still.

Get a quote to have the batts replaced though. I had mine supplied and installed for less than I could have bought the batts for.

[squashedfrog1]

Also shop around for your batts. I found a place in Melbourne (robot trading) that sells batts for nearly half the price of Bunnies and even the batt stores!

For some weird reason the polyester batts were cheaper than fibreglass if you bought 1.5's and fibreglass cheaper than poly if you bought 3.5's.

If you diy fibreglass make sure you go full protection gear, mask, coveralls etc.


sf

[tony123]

Also shop around for your batts. I found a place in Melbourne (robot trading) that sells batts for nearly half the price of Bunnies and even the batt stores!

For some weird reason the polyester batts were cheaper than fibreglass if you bought 1.5's and fibreglass cheaper than poly if you bought 3.5's.

If you diy fibreglass make sure you go full protection gear, mask, coveralls etc.


sf

Can I just lay the new batts over the existing batts ?I'm considering buying some R1.5's and laying them over the existing batts. Hopefully this will increase the rating .tony

[silentC]

You might also find that some low rating batts are cheaper and probably more effective if you install them over the old ones.

[bricks]

I dont think covering your batts will work that well because they trap air whic becomes the insulator, sarking normally goes under the tiles or sheets.

For cheap alternative my dad ( tite as a ducks......) rips up every newspaper he ever buys and puts that in the roof, he tells us it helps with the insulation and that his dad did it during the depression and ...... blah blah blah

If you do put your own insulation you have to keep it away from ignition sources like lights and power sockets, when i install gas flues i have to keep the insulation 150mm away and power i think is the same. Might pay to ask an electrician or the guy who sells you the batts. They should know.

The only thing everone will agree to is that i know nothing about electrical work.

[ausdesign]

Can I just lay the new batts over the existing batts ?I'm considering buying some R1.5's and laying them over the existing batts. Hopefully this will increase the rating .tony

Yes. Fit them in snugly so there's no gaps to get the maximum benefit.
As a guide - 80mm fibreglass = R1.6
100mm = R2.1
130mm = R2.6
150mm = R3.0
200mm = R4.0
If you can do it easily 'fluff' up the originals to improve perfomance but don't bust a gut as the added benefits not 'mind blowing'

Is it a tiled roof or steel ?
If tile with no sarking then installing sarking [under the tiles] will benefit the thermal performance by creating whats referred to as 'an enclosed roof space'.
If its iron with no sarking then installing sarking will be a big benefit.
Either case you'll need to abide by OH & S and around 6 other reg's & requirements so that puts it ouside the scope of a DIY project.

Added - I don't think newspaper meets the flamability index requirements of the current reg's.