Thread: What kind of insulation is this?

This in a 1940s house in Northern Virginia: It's light and cotton-like. The chocolate color may be age related.

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It appears to be what we always called "Rock Wool". Nasty stuff that readily becomes friable and airborne. Visit this site for some good info about the stuff.
Safety of Rock and Slag Wool Insulation

Originally Posted by Holli Brown

This in a 1940s house in Northern Virginia: It's light and cotton-like. The chocolate color may be age related.

Originally Posted by Bob Knauff

It appears to be what we always called "Rock Wool". Nasty stuff that readily becomes friable and airborne. Visit this site for some good info about the stuff.
Safety of Rock and Slag Wool Insulation

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Good morning Bob,

As this Material has a Hint Of Pink Color. ( Fiberglass )
* which is Copyrighted by Copyright 1996 - 2010 Owens Corning
** but a home of that era could very well have an under base of " Rock Wool "covered over.
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Yeah, I thought of that too Billy...Rock Wool tended to be more greyish in color but the fact that the stuff in this photo is so thin and flat and sparse looking kind of steered me away from fiberglass. Might be an early version of fiberglass, before they perfected it to be big and fluffy tho.

Thanks for the feedback guys. In my thinking, I've ruled out rock wool; It's to light and fluffy. And no, I don't think the pink has anything to do with Owens Corning.

My client was concerned about asbestos content. I told him I didn't think that was likely to be an issue, but that I'd follow up. If anyone else has any more insights, I'd appreciate the feedback.

Hollis

Originally Posted by Billy Stephens

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As this Material has a Hint Of Pink Color. ( Fiberglass )
* which is Copyrighted by Copyright 1996 - 2010 Owens Corning

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Originally Posted by Holli Brown

. And no, I don't think the pink has anything to do with Owens Corning.

Hollis

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I Hope Owens Corning Don't Find Out someone else has manufactured a Pink Color Insulation.
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Hehehehe... I don't think they're going to care.

Originally Posted by Holli Brown

Thanks for the feedback guys. In my thinking, I've ruled out rock wool; It's to light and fluffy. And no, I don't think the pink has anything to do with Owens Corning.

My client was concerned about asbestos content. I told him I didn't think that was likely to be an issue, but that I'd follow up. If anyone else has any more insights, I'd appreciate the feedback.

Hollis

Through a propane torch to it...if it doesn't melt, it's most likely rock wool. IF it melts through to the ceiling, call the fire department .

Well, even if it is something akin to rock wool and therefore as dangerous friable as asbestos fibers, it can simply be covered up with a lot of blown cellulose that will effectively encapsulate it so it becomes a non-issue. It appears the space could use another 18 inches of insulation regardless! The more insulation the more occupant comfort and less energy usage/utility costs.

Originally Posted by Bob Knauff

Well, even if it is something akin to rock wool and therefore as dangerous friable as asbestos fibers, it can simply be covered up with a lot of blown cellulose that will effectively encapsulate it so it becomes a non-issue. It appears the space could use another 18 inches of insulation regardless! The more insulation the more occupant comfort and less energy usage/utility costs.

Bob, this is a quote from the site you linked in your first post.

Findings from all types of studies have been consistent. Airborne levels of respirable rock and slag wool fibers have been demonstrated to be very low, less than one fiber per cubic centimeter of air (1 f/cc) in most instances. Studies among workers have demonstrated no consistent association between lung cancer or non-malignant respiratory disease and occupational exposure to rock and slag wool.

Why do you say its nasty stuff and associate it with asbestos?

Originally Posted by Holli Brown

This in a 1940s house in Northern Virginia: It's light and cotton-like. The chocolate color may be age related.

I think you pegged it when you said "Cotton-Like"
It very well could be cotton. Cotton was common in pre-1950 homes. especially in areas of the country where it is available or produced.

Many building materials seam to make cycles in their use. What was used 50 or 100 years ago seams to come back in a "New and Improved" form.

My other business is that of an insulation contractor (25 years). In that time we have seen 100 year old homes being remodeled. they have rolled up newspapers in the walls...we replace it with>>> "Newspaper" (Cellulose) improved to make it fire proof and spray-able.

We have all seen where "Adobe" walls are being used as if they are something new!

Now, what you discovered (probably cotton) is coming back as a "new" insulation....made from old Blue Jeans.

"Everything old is new again"