What type of insulation is this ?

[Sam Morris]

This home was built in 1954, the first layer of insulation was rockwool, but white small balls and chunks I don't remember the official name of this material ?? (looks like Styrofoam and similar to the ice cream Dip and Dots if your familiar with that)

[Sam Morris]

This home was built in 1954, the first layer of insulation was rockwool, but white small balls and chunks I don't remember the official name of this material ?? (looks like Styrofoam and similar to the ice cream Dip and Dots if your familiar with that)

I think its called Perlite Insulation

[Gunnar Alquist]

This home was built in 1954, the first layer of insulation was rockwool, but white small balls and chunks I don't remember the official name of this material ?? (looks like Styrofoam and similar to the ice cream Dip and Dots if your familiar with that)

Sam,

Did you just answer your own question?

Until I read your question and answer, I was unaware that perlite was used for insulation (although it does make sense, now that I think of it). I know that it is used in gardening as a soil additive but have never seen it used in a residence. Vermiculite is not uncommon in that age home, but your pics don't look like vermiculite.

The pictures that I found online show perlite insulation as between the small pieces and larger chunks that are in your images. It makes me wonder if you really do have polystyrene. Did you handle any of it? Polystyrene will squish easily, but perlite is a bit more difficult to crush and turns to a white powder.

Perlite Image (https://www.perlite.org/wp-content/uploads/2022/10/Perlite-Sustainable-Insulation.pdf)
Vermiculite Image (https://www.health.state.mn.us/communities/environment/asbestos/images/verm_tev_capt.jpg)

In short, I dunno. Sorry.

[david shapiro]

Sam, it could easily be perlite. However, I wouldn't ignore Gunnar's suggestion of vermiculite, even though the pieces doesn't have the striations I've seen. AND if it should be vermiculite, that could mean some asbestos is admixed. Photos don't have to show discrete particles with the spikey look.