Old insulation in attics of row homes

[Joeolney]

Does anyone know what that insulation in the second floor ceilings found in older homes is made of? It looks like loose pieces of cotton/wool.I'll post this over in the Architecture forum as well but figured I would post it in here as well since someone surely has gotten rained on with this stuff when putting up a ceiling fan.

Thanks,

Joe

[Radical Ed]

That sounds like vermiculite asbestos. Bad stuff.

[borntochill]

If it looks cottony that doesn't sound like vermiculate asbestos to me. It sounds like rock wool:

Rock Wool and Slag Wool Insulations for Residential and Commercial Envelope Applications - About Insulation : NAIMA North American Insulation Manufacturers Association

Rock wool is not a dangerous material like asbestos.

[Joeolney]

If it looks cottony that doesn't sound like vermiculate asbestos to me. It sounds like rock wool:

Rock Wool and Slag Wool Insulations for Residential and Commercial Envelope Applications - About Insulation : NAIMA North American Insulation Manufacturers Association

Rock wool is not a dangerous material like asbestos.

whew, been reading a bunch about the vermiculite asbestos since Radical Ed's post but I am glad to see your post about rock wool. It definitely seems more cotteny/wool like and when looking at pictures of the two types, it seems to resemble the rock wool versus the vermiculite. Would rock wool have been used in the '30 when my home was built? My only reason for this concern is the I just had a High Velocity Central Air system installed this past week and the guys had to cut a big panel for access in my bedroom in the bedroom. So there was stuff flying around from that. They said it wasn't asbestos and I figured they would know since it's their livelihood but I'm just a bit skeptical sometimes.

Seems like the vermiculite looks more like stones versus the wool look of the rock wool. How do I know for sure?

[John Arnold]

...Seems like the vermiculite looks more like stones versus the wool look of the rock wool. How do I know for sure?

Does not sound like asbestos/vermiculite, but asbestos can show up in many construction materials. How do you know for sure? You have a sample tested.

[Joeolney]

Does not sound like asbestos/vermiculite, but asbestos can show up in many construction materials. How do you know for sure? You have a sample tested.

Thanks John. I was hoping to know though how to tell the difference between the Vermiculite and the rockwool insulation. It seems as though, from googling images, that the Vermiculite looks more like small stones or painted styrofoam peanuts versus the wool appearance of the rockwool

[borntochill]

According to this site, the rock wool that was historically used for residential insulation does NOT contain asbestos. In 1930 when your home was built, rock wool was a common insulator in residential construction. I understand it's a good insulator, but typically too little was used back then.

[Joeolney]

According to this site, the rock wool that was historically used for residential insulation does NOT contain asbestos. In 1930 when your home was built, rock wool was a common insulator in residential construction. I understand it's a good insulator, but typically too little was used back then.

Yeah, I have read that too, about it being a good product but too little was used. That is certainly that case in my crawlspace. It covers that whole area but I don't even think it was three inches deep.

[dcss1205]

If you have access, consider adding more, by whatever means you can, baged, roll etc.
Pay attention to the "coners where an outside wall meets the ceiling wall, and add more there,
If you have lathe & plaster, the air movement in the gap would be reduces.

Since I can access my ceiling, I rented a machine and blew in loose rock wool, myself,
But that was in 1980-81.