Sometimes members of the starling family have historically been called grackles. Tristram's starling is sometimes known as Tristram's grackle, and the hill mynas in the genus Gracula have also been called grackles.ometimes members of the starling family have historically been called grackles. Tristram's starling is sometimes known as Tristram's grackle, and the hill mynas in the genus Gracula have also been called grackles.
Waterproofing an old limestone foundation from the exterior with âClosed Cellâ spray polyurethane foam provides a water tight seal from the outside.
With foamed-in-place insulation, it is relatively easy (though not inexpensive) to fill wall and ceiling cavities completely. Closed-cell spray foam provides a higher R-value Measure of resistance to heat flow; the higher the R-value, the lower the heat loss.The inverse of U-factor. per inch (6.5) than less expensive insulation types like cellulose and fiberglass (3.5 to 3.7). Most spray polyurethane foam is called two-component foam.-value Measure of resistance to heat flow; the higher the R-value, the lower the heat loss. The inverse of U-factor. per inch: about 3.6. Cost: about $0.44 to $0.65 per board foot. Although open-cell foam costs less than closed-cell foam, it has a lower R-value per inch, so a thicker layer is required.