Attic Insulation

[vinny11950]

Thanks, again, Woodgeek. I appreciate the time and knowledge you share here.

 

[semipro]

I haven't researched it much, so I don't know if FB has some horrible environmental impact that makes Greenbuilders say negative things about it.

The (environmental) problem with fiberglass is that its rarely installed well, and as noted in the article, this is at least partly due to how hard it is to work with. This results in wasted energy.
Having worked with both FB and Roxul I can see where the Roxul is almost hard to install poorly whereas the FB takes great care to install correctly.
I suggest naysayers try the Roxul before they knock it.

 

[semipro]

What a stupid article.

Always glad to help out.

 

[Highbeam]

Hah! Did you even read it?

 

[Lake Girl]

Every one has their preference... I know I hate working with fiberglass so I wouldn't mind working with Roxul to compare for myself.

 

[semipro]

Hah! Did you even read it?

Of course I did, before I recommended it here as "good".
The author compares fiberglass and Roxul batts. He recommends Roxul based on:

• Easier to work with (cutting, placing, etc.)
  
• Less irritation to skin, eyes, etc.
  
• Low embodied energy
• High recycled content
• Better R value than commonly available FB batts.
  
• Water repellency(sp)

I can attest to what the author is saying as far as ease of use and lack of irritation. I've been using it in a basement sealing/insulation project. The photos below show the Roxul installed in basement walls inside of XPS foam against concrete and in the rim joist area (also inside of XPS). I've been installing this stuff with a tee shirt on, something I could never do with fiberglass. When working with fiberglass I cover all skin, use an air filter, and try to wear goggles -- what a pain and I still suffer when I'm done. I've tried both the newer styles Johns-Mansfield and Owens Corning and they still tear up my skin, eyes, and lungs up.
I'm pretty tough skinned too. The day before working on this I was feeding wood, vine, briars into a chipper/shredder on the back of my tractor without sleeves for safety.

 

[Highbeam]

Every one has their preference... I know I hate working with fiberglass so I wouldn't mind working with Roxul to compare for myself.

I may have used it on my current insulation project but the roxul was very expensive and only available in two sizes that were only for walls. No R-38 batts, or R-30 or, faced, or. .... None of the benefits vs. FG, other than perhaps less irritation, are of any significant value and the author of semipro's article does a terrible job making his case.

I've been convinced that cellulose is as good as fiberglass blown in so I was really hoping for some reason to think that roxul is worth the extra cost in a batt application. Of course, it's not even available is most sizes anyway. Lowes sells denim insulation now too. Maybe there's an article somewhere about how they only use recycled jeans from hot chicks and that is why you should use denim insulation.

 

[Lake Girl]

Of course hot chicks are involved - Denim insulation meets the standard for indoor air pollutant testing for California Public Schools Actually interesting specs but still does not have the fire and smoke spread rating of zero like Roxul.

 

[brian89gp]

Rodents seem to avoid Roxul more often then they do fiberglass and can be used as fire blocking. The higher density Roxul (which sucks at insulating btw) is a decent sound barrier. Also doesn't seem to mold like fiberglass does.

 

[vinny11950]

Thanks for the tips guys and gal. Like always, I have been detoured the last two weekends for Jeep maintenance (radiator, cooling lines, gas lines, etc... the Cherokee forum guys love me.... not).

Anyway, I hope to pick up the project soon before it gets too hot.

 

[Highbeam]

Rodents seem to avoid Roxul more often then they do fiberglass and can be used as fire blocking. The higher density Roxul (which sucks at insulating btw) is a decent sound barrier. Also doesn't seem to mold like fiberglass does.

All of that sounds like BS except that Roxul is a decent sound barrier. Neither FG or roxul is a food for mold so neither will support mold but like a shower stall wall, mold can grow on anything in the right conditions.

 

[semipro]

Rodents seem to avoid Roxul more often then they do fiberglass

I hope this is true but I have my doubts. I can attest that mice like fiberglass.... a lot.

 

[Highbeam]

I hope this is true but I have my doubts. I can attest that mice like fiberglass.... a lot.

Me too. I've found some pretty intricate tunnels in wall batts. It's a warm, dry, soft place to set up a home. Is it a surprise that animals want to live there? The manufacturers make insulation less itchy and scratchy so that mammals like us enjoy installing it but mice are mammals too.

Don't depend on your insulation to keep mice out.

 

[semipro]

Don't depend on your insulation to keep mice out.

Agreed.
That said, there is a new type of Great Stuff spray foam that supposedly deters rodents.
http://greatstuff.dow.com/products/pestblock/
We're trying it out at work where some mice have gotten into optical fiber and chewed through it.

 

[brian89gp]

All of that sounds like BS except that Roxul is a decent sound barrier. Neither FG or roxul is a food for mold so neither will support mold but like a shower stall wall, mold can grow on anything in the right conditions.

Talked to a bulding inspector that said roxul was a possible substitute for fireblocking. I have seen an unfinished wall with both roxul and fiberglass in it and the fiberglass was shredded by mice, the roxul untouched. Flukes? Perhaps, but I have heard others stating the same things from experience.

As far as mold I have no direct personal experience. Perhaps it is more difficult to mold since roxul doesn't really absorb water while fiberglass is almost a sponge?