Rock wool?

[Tim Larsen]

60+ year old house. Original faced wall insulation.
Is this faced rock wool, or dirty glass?

TIA,
Tim

[Brian A. MacNeish]

Originally Posted by tlarsen

60+ year old house. Original faced wall insulation.
Is this faced rock wool, or dirty glass?

TIA,
Tim

By the colour and if original, I'd say "rock wool"

[Joseph Hagarty, CMI]

gray black
Rock Wool....
better than fiberglass....

[Tim Larsen]

Thanks, guys. I thought so, but I've had no previous experience with it.

Cheers,
Tim

[Bob Elliott]

Learn how to do it the easy way.
Mineral wool/fiberglass type material.

[Christopher Currins]

It's not Perlite.

[Jeffrey R. Jonas]

Originally Posted by ccurrins

It's not Perlite.

[Joseph Hagarty, CMI]

Originally Posted by ccurrins

It's not Perlite.

????
rock wool
no comparison

[Christopher Currins]

Originally Posted by jhagarty

????
rock wool
no comparison

http://www.nachi.org/forum/f11/attic-insulation-61322/

[Brian A. MacNeish]

Originally Posted by jhagarty

gray black
Rock Wool....
better than fiberglass....

Reasons?

I tend to rate them as near equals for R value & installation except when it comes to cost......rockwool batts are more expensive than fiberglass batts here!!

With higher R values (up to R50 in attics) in todays' much more efficient homes, the extra weight of the heavier blown rockwool on flat attic surfaces may require 5/8" drywall or thicker on the ceiling.

For example: 1 brand of rock wool I looked up had a weight or 2.68 lbs/sq ft for R34. Cellulose is 1.23 lbs/sq ft for the same R value.

[Joseph Hagarty, CMI]

???
pic in first post looks like perlite?
????

[Joseph Hagarty, CMI]

all insulation is inadequate at best to the claimed (R) values.
Installation methods may vary......

[Scott Gilligan, CMI]

The easy way to tell is to take a hot shower after you get home from the inspection. If you start itching so bad you can't write up the report, it was fiberglass.

[Jeffrey R. Jonas]

Originally Posted by jhagarty

???
pic in first post looks like perlite?
????

Perhaps a "tongue-in-cheek" reference to this thread... http://www.nachi.org/forum/f11/attic-insulation-61322/

BTW... post #13 is still awaiting your reply.

[ROBERT V. YOUNG]

Originally Posted by Brian A. MacNeish

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Reasons?

I tend to rate them as near equals for R value & installation except when it comes to cost......rockwool batts are more expensive than fiberglass batts here!!

With higher R values (up to R50 in attics) in todays' much more efficient homes, the extra weight of the heavier blown rockwool on flat attic surfaces may require 5/8" drywall or thicker on the ceiling.

For example: 1 brand of rock wool I looked up had a weight or 2.68 lbs/sq ft for R34. Cellulose is 1.23 lbs/sq ft for the same R value.

I agree with you hypothesis on the 5/8 wallboard.
Imagine the weight the the RW will have if it carries moisture.
Q: What is rockwool?
A: Rockwool is spun mineral wool fiber. Various "rock" components, with a heavy dose of silicon oxides are melted at high temperature and fibers are formed as molten material is passed by a series of "spinners." The finished product which is "bonded" via proprietary resins, is inert, meaning it has no cation exchange capacity. Approximately 97% v/v/ is air space. Bonded products (plugs, blocks and slabs) also contain a wetting agent, which may (absorbent) or may not (repellant) be present in granulated (also called flock) rockwool.