ON TOPIC, cheap old attic insulation FAQ

Blown-in? Made of cellulose IIRC.

Probably rock wool.

A quick google search :

micky can google up pictures of cellulose and rock wool and should be able to tell which it is.

If loose fill, it's better. If it batting (roll). R-38 is typical for attics. Baltimore isn't Alaska.

Trying to answer everyone at once.

By adding "history" to my search terms, I found the words I was looking for.

Rock Wool, which is not made from sheep but from rocks!!

My house was built in 1979 and just has this stuff in the attic, spread over the ceilings.

Blown-in is a method of application, used especially on pre-existing homes that didnt' get enough insulation. In my case, I think it would have come in bags and been spread before the roof was put on, but I welcome contradiction.

it's about 3" thick and I'm thinking it may have been deeper at the start and settled.

The house also has fiberglass batts in the outside walls.

Curious in the first place plus wanted to make sure that it didn't contain asbestos, although if asbestosis takes 20 or 30 years to develop**,, I'm probably safe at age 77. Plus after the first 10 minutes I wore a KN95 mask. Were there asbestos, I think that unlike germs, asbestos is much bigger and even a lesser mask would work, but I have no lesser masks.

Rock Wool was known for its blowable insulation called rock wool or mineral wool. This type of insulation does not typically contain asbestos. But testing showed that some companies that produced rock wool added asbestos. Rock Wool was among the companies that did, leading to many claims of asbestos exposure.Jul 18, 2023 Rock Wool Manufacturing Co. | Asbestos Use, Products ...

The wikipedia page for mesothelioma seems to say 40 years. It's a burden but I will see if I can hold on to age 117.

But I also read "Commercial asbestos mining at Wittenoom, Western Australia, took place from 1937 to 1966. The first case of mesothelioma in the town occurred in 1960. The second case was in 1969, and new cases began to appear more frequently thereafter. The lag time between initial exposure to asbestos and the development of mesothelioma varied from 12 years 9 months up to 58 years.[42]" After 12 years I'd only be 89, but I don't work with this all day like some did.

One lawfirm seeking customers on TV pronounces mesothelioma with the first e long. As I suspected, it's short.

Thursday night, about 11:30, about half of my bedroom ceiling fell down. I was in the other room, and it sounded,for 5 or 10 seconds, like bookshelves falling. More fell later. My bedroom is about 21 feet by

I can see the front of my roof from the ground, and it looks fine, but not the back, which faces south*** and ages faster. I tried a PC camera on a long stick -- that was to look in the gutters, -- but couldn't point it the way I wanted. Then I bought a cheap used drone, but they are hard to fly. I have to practice more or buy a newer one that is easier. Or go up in the attic during a rainstorm. It was raining, Thursday day. Maybe one part got wet and since it's taped to other parts, it brought them down too. The nails used were only 1 1/4 and the sheetrock is, without measuring it, 3/8" so that doesn't leave a lot in the wood. None of the ceilings in othrr rooms show any signs of sagging.

Immigrant Democrat squatters living up there ? :-) John T.

No, not squatters. Part of the Overground Railroad, a way station on their way to Canada.

And now that I got enough out so I can enter the bedrroom, it's more like 75% of the ceiling fell down. I'm sure most was in good condition but the part that fell dragged down the rest.

I did do some damage 40 years ago, I suspect, by putting weight on the trusses, causing them to flex I think. When I was first putting in the ceiling light fixture and the wall switch by my bed on the outside wall, running another phone line, speaker wires, extension TV cable to the other rooms. That's above the bedroom

In the center I put in a floor 16" x 8' sheets of plywood and later when someone gave me a pile of 2'x 2' plywood I added that, then stored things like old papers, a lava lamp (which froze and broke), the flag from my father's casket, and I installed an amplified tv antenna and later a different one. And I stood on the floor when I ran the elctricity for the roof fan and the light on the side of the house. But that part of the ceiling, the hall, the stairwell, the bathrooms, looks fine.

I thought I had a real, but unfinished, attic, but I heard later that trusses don't count. And in a few places in the bedroom ceiling where the 4x8 sheets met, there was a little paper roll, up to I guess 4' long, where I guess I had forced down one sheet and lifted up the paper from the adjacent sheet, then when I got off, it folded back. But it's been like that for 5 to 35 years.

Now I have a cathedral ceiling. Services will be weekly.

You said earlier that they used nails not screws ? for the ceiling sheetrock ? I'm guessing that the flexing of the joists - caused by your many various activities in the attic - caused not-only the "roll" at the joint but loosened the nails enough that they finally let go. Add some bracing and use screws. John T.

So, what broke. The joists or trusses, or the wallboard? If the wallboard, how did it get weight on it? A big leak of water?

Cellulose???? Basically schredded newspaper treated with borax.

Both cellulose and rock wool are blown in. I think rock wool might also be brought up in bags. Rock wool I have seen is gray. Cellulose is the color of fiberglass insulation (that is what it is). Rock wool was used longer ago - 3" gray is very likely rock wool. Cellulose is used now when the importance of insulation is better understood, and is likely over the joists. Cellulose is fluffy and low density. Rock wool is much higher density. A mask is a good idea with cellulose.

Some Vermiculite had asbestos.

Interesting - never heard rock wool might have asbestos

Señor Mickey, I'm guessing an unvaxxxinated invader-voter installed your drywall and didn't space the fasteners properly.

From USG FAQ: "

When nailing to wood construction the spacing is 7 inches for ceilings, and 8 inches for walls.

When screwing into wood and steel framing the spacing is 12 inches on ceilings and 16 inches for walls.

Refer to the relevant fire test to determine fastener type and spacing.

Cellulose is absolutely NOT fiberglass, or the same color as fiberglass.

Been a long time since I had to crawl around in attics and I don't remember any of them were celulose. But you are right it is different from blown fiberglass.

Not true. Loose fill fiberglass is NOT CELLULOSE. Cellulose is plant fiber - generally wood fiber - - usually recycled newsprint which has been run through a hammermill.

Real good idea with rockwool too. Rock woolis made from smelter slag.