Owens Corning Insulation

Here’s some info to tuck away in your For What It’s Worth File.

I recently inspected a home where the owner was present. When identifying the newer loose fill white mineral wool insulation to the buyer, the seller insisted that it was “fiber glass”, he installed it himself, and it came in bags from the big box store, and was labeled “Owens Corning”.

I politely said “Oh?” and then pointed to the words “Mineral Wool” to my client.

Understanding that I don’t know everything, I followed up with a phone call today to Owens Corning. The lady I spoke to said that they had sold loose fill mineral wool years ago, but even then it was pink and not white. Today they only sell fiberglass, and everything they sell is pink (rolled or loose fill.)

I don’t know about the likelihood of “White” loose fill fiberglass, but my seller was obviously wrong about it being Owens Corning.

Anyone know of a “white” loose fill fiberglass? The picture I posted on this site at the time, everyone said looked like mineral wool to them. So I’m pretty sure the seller was wrong about that too.

Climate-Pro makes white fiberglass loose-fill. I’m sure there are others.

White loose fill or blown insulation Mark here;

Not sure if that was the question you were asking. :):slight_smile:

I see it frequently in my area.

Okay, at the risk of asking a rookie question…

How do you tell the difference between white fiberglass, and white mineral wool?

Rock wool is also known by the names mineral wool and slag wool. It is a type of insulation material that is used in the attics and walls of buildings. Rock wool is a natural fiber that looks like tiny little balls.

Also comes white. :slight_smile:

This is frustrating for me, because (other than it not being pink) the white looks just like loose fiberglass… actually the gray doesn’t but the white does.

If the picture on the left is actually fiberglass, then I think I’ve been miss-identifying some insulation recently. Because that is exactly what I’ve been identifying as mineral wool and is what was identified as mineral wool on this message board.

Is fiberglass more “fibery” and mineral wool more like cotton?

(I know this is probably remedial, but it’s not something I’ve had come up before… sorry if I’m being thick. I just really want to understand. )

I see it alot here too.

We have white loose fiberglass here also. One way to tell the two apart is if you get fiberglass in your crack it’s irritating and if you get Rock Wool in your crack you will be sure it never happens again.


I see fiberglass that appears “cotton candy” like texture and mineral wool like raw matted sheep’s wool looking.

Make sense?

*Mineral Wool *insulation is making a comeback after losing its market share to fiberglass in the 1960s and 1970s. “Mineral wool” actually refers to two different materials: slag wool and rock wool. Slag wool is an industrial waste product produced from iron ore blast furnace slag. Rock wool is produced from natural rocks of basalt and diabase. Slag wool accounts for approximately 80 percent of the mineral wool insulation industry and contains 70-90 percent post-industrial recycled content. It is available as blow-on wall insulation (a starch binder is used), as loose blow-in attic insulation, and as batts. It offers very good energy performance, will not burn, and is chemically inert. Mineral wool fibers are similar to fiberglass in their ability to become airborne and be inhaled.


Also see here for additional information on different types.


Thanks guys. I’ll look at the “white” stuff a little closer in the future.

Curtis, I appreciate your comment, but I think I’ll take a pass on your method of determining which is which. :wink:

Some OC fiberglass blowing wool in Canada is called “Propink” but they definitely cut back on the colouring because it’s almost white with a slight pink hue to it. You might mistake it for white in poor lighting.

If you’re referring to this post Mark;

it looks morelike this, (Rock Wool), 3rd photo down, than it does fiberglass. Also using your description. It is difficult to positive ID on the message board.

No that’s a much older post…

This would be a great subject for Nick to write an article on… all the common types of insulation we run accross, with descriptions and quality photo’s… Hi-Res close-ups… and I’m talking close, as in macro… not three feet away. Most all pic’s are not close enough for proper detail and identification.

In my neck of the woods there’s always a data plaque at the hatch telling what kind of insulation and required R value / thickness.