R19 Fiberglass ?

[Brownee]

Hi, can someone help a noob?

Here in Australia I can't find R19 fiberglass insulation. It seems that either we use a different rating system or we don’t have the same insulation. My local suppliers sell bats with a rating of R2 to about R6.
Can someone clear this up for me please?

Thanks

[Ron E]

R11 fiberglass is made for 2x4 walls
R19 is made for 2x6 walls

turns out to convert Inch-Pound to metric you multiply by 0.176
R11 = ~R2
R19 = ~R3

[Brownee]

Thanks for that Ron.

I'm still a little confused. As you go up in R rating does the material get denser?

It looks to me that the difference between say R13 and R19 is only the thickness, not the density. Or am I wrong?

So, if I wanted to put say 1-2" of insulation on the walls of a vented enclosure it wouldn't mater what rating I used because I only need 1-2" .

This raises another question. to get 1-2" thickness do you pull the insulation apart? Is it built in layers?

Thanks.

[Cal Weldon]

We must cheat a little 'cause those ratings become R20 and R12 in Canada.

Yes you can separate the fiberglass into layers, kinda, sorta. It's not a perfect layer but it's not that critical.

The densities should be the same once you relax the insulation a bit.

[Ron E]

I think maybe the reason for the reduction is that 1.5/16 or 1.5/24 of the wall is studs.

Fiberglass does separate a bit - it is really itchy nasty stuff if you have never worked with it before. A dustmask and gloves and a long sleeve shirt are required if you want to minimize discomfort.

There is nothing wrong with placing multiple layers of dacron used for quilts on the walls. That stuff is nearly as effective as fiberglass and there is no itch. If all you can find is pillow stuffing you could make bags out of netting and tack them to the walls.