Anybody know about glass bead insulation
I have an 85 year old cape, and the first floor exterior walls were insulated with Urea-Formeldehyde in the 70s. From the basement, I could see one stud bay was left uninsulated because it had live knob and tube in it. The Knob and tube is no longer connected to any live circuits.
I had a need to get another circuit to the second floor, so I tore the plaster off the gable end wall on the second floor. This may seem radical, but there was no insulation behind this wall. I have fished a 12-2 wire through the empty bay, plus some flexible conduit conduit for future low voltage uses.
I would like to insulate this bay before I close the wall back up. I have a large opening in the basement, and I can drill a few more 1 inch holes through the bottom plate of the 2nd floor wall + the top plate of the first floor wall. It doesn’t pay to get a contractor out to spray foam for one stud bay.
I recall hearing about a “glass bead” insulation back in the 70’s that would be perfect. These beads were like puffed rice. There are completly inert, and no water is required for installation.
I could use spray foam to fill in the bottom of the bay, and spoon feed the beads through a 1″ pipe (We are talking one bay here). Unlike loose Cellulose or Fiberglass, the beads would not get caught on the plaster lath or the knobs and wire, so there shouldn’t be any voids.
I have searched the web for these glass beads, but I am coming up empty. I am looking for the wrong thing, or was there a problem that caused this type of insulation to disappear from the market? Heck, Id even consider filling the cavity with sand, which would give me some R value.