I have an 18" diameter X 3' stand pipe in my yard that has a pvc water pipe
coming up through it with a hose bib on the end. Because I live in a
freezing winter environment I wrapped the pvc pipe with fiber glass
insulation. I now want to fill in the space between the fiber glass wrap
and the interior of the stand pipe with an insulation material. Any
suggestions on what I could put in that space that would be a good
insulator?