Identifying old insulation

[MikeC55]

I'm having an addition added to my circa 1956 wood frame home and noticed the original (I believe) attic insulation, which was later covered with fiberglass batts, has been exposed in some areas. I'm concerned that it may contain asbestos and have taken a sample to get tested. From the descriptions I've read (for example:https://www.thisoldhouse.com/insulation/21017698/how-to-know-what-insulation-is-behind-your-walls), I think this stuff is rockwool. It definitely does not have any shiny particles. Unfortunately, the paper backing has no identify marking (not sure if the paper started out black). What do you guys think?

 

[PCustoms]

I'm having an addition added to my circa 1956 wood frame home and noticed the original (I believe) insulation, which was later covered with fiberglass batts, has been exposed in some areas. I'm concerned that it may contain asbestos and have taken a sample to get tested. From the descriptions I've read (for example:

I think you're missing something....

Is a contractor doing the addition?

Aren't they responsible for abatement? What did they do for the lead paint?

 

[MikeC55]

It is a contractor doing the work and I'm going to bring it up with him. I didn't think about lead paint, but that ship has sailed. The debris from existing wall demo was carted away months ago. I thought lead paint required eating it to cause health problems.

 

[PCustoms]

It is a contractor doing the work and I'm going to bring it up with him. I didn't think about lead paint, but that ship has sailed. The debris from existing wall demo was carted away months ago. I thought lead paint required eating it to cause health problems.

Still (legally) requires abatement in most areas.

A contractor walking in to a job on a '56 house should be able to identify if there are potential hazards that would require mitigation.

If it is asbestos, and it's been disturbed in an open environment you might be in for a bigger project.

Good luck!

 

[MikeC55]

Thanks. I'm sending out the sample for testing tomorrow. I think the fact that it's paper-backed makes it less likely to be vermiculite, which was usually a loose fill (from what I've been reading).

 

[PCustoms]

Thanks. I'm sending out the sample for testing tomorrow. I think the fact that it's paper-backed makes it less likely to be vermiculite, which was usually a loose fill (from what I've been reading).

Paper backed is not vermiculite. Period.

 

[The Cobbler]

you have fiberglass batt & cellulose . vermiculite looks like small crushed stone

 

[MikeC55]

I think you guys are correct, but it doesn't cost much to get it tested. Assuming it is safe, the next worry is the vapor barrier. This stuff was installed with the paper side up (away from warm surface ceiling) and is only 2 -3" thick (joists are 2 x 6). I hate the thought of ripping all of this out, but from what I'm reading, it seems like the correct thing to do (and replaced with faced fiberglass, facing against the ceiling). I should add, the stuff crumbles to the touch, so it will be a really messy job.

 

[4x4Pete]

Regarding the ceiling, if it crumbles now, you could put vapor barrier (6mil poly) on the ceiling and then blow in insulation on top? Blowing in would crumble the paper and pretty much destroy any vapor barrier it currently has? I think paperbacked insulation should have been left in the '70s

 

[MikeC55]

I'm thinking maybe to get up there with a shop vac and HEPA filter and vacuum out as much of it as possible, then remove all of the paper that's left and start fresh with R-19 faced batts. I would then add unfaced R30 bats perpendicular to the joists. Another room that was added on back in the 60s has fiberglass batts, but with backing facing attic. I'll have to flip these over... I guess whoever did this place didn't read the memo on where to put vapor barrier...

 

[dscheidt]

I'm thinking maybe to get up there with a shop vac and HEPA filter and vacuum out as much of it as possible, then remove all of the paper that's left and start fresh with R-19 faced batts. I would then add unfaced R30 bats perpendicular to the joists. Another room that was added on back in the 60s has fiberglass batts, but with backing facing attic. I'll have to flip these over... I guess whoever did this place didn't read the memo on where to put vapor barrier...

if you remove the old insulation, air seal before replacing it.

 

[geneg]

Hire an insulation contractor to remove the existing material. They'll bring in a machine similar to the duct cleaning vacuums. It sits outside & a 6 or 8 inch hose is used to **** out everything. A shop vac is painful to use for this, it will constantly plug the hose & you'll be handling everything at least twice. You'll then have a clean area to airseal, foam, or blow in insul.

 

[MikeC55]

Thanks, guys. By 'airsealing', I think you mean foaming around all ceiling penetrations. Anything else?

 

[dscheidt]

foam is one effective way to do it, yes. But there are other things you can do, including plain old caulk, putting insulated boxes around light fixtures, and metal flashing. (You can't foam an actively used chimney, for example, so caulk and metal are used there). The basic idea is to keep air from moving from the conditioned part of the house into the attic. It greatly increases the effectiveness of the insulation, and since it's basically impossible to do with insulation in place, now is your chance. There should be some stuff on green building advisor about it.

 

[The Bean]

I had old blown-in insulation removed from the attic of my 1927 home during a renovation almost 20 years ago. The sub-contractor used a vacuum system connected to a truck outside and long big hoses. What remained was small green spherical glass 'sand' in the joist bays that we swept up. I don't know what the make up of the insulation was.
Also, the heating pipes in the basement did and some still do have asbestos in the gause wrapping applied to the fiberglass insulation which consists of two half cylinder lengths sandwiching the pipes. Does that ring a bell with anyone?