Ok, being that I am a foam guy I must tell you that I not only like foam, but I like almost all insulation (except batt insulation). Some insulations are just better for certain jobs than others.
Take dense pack cellulose, for example. This involves the cellulose insulation being densely packed into the cavities of a house using 2.5 to 4.5 pounds per cubic foot of pressure, which in turn “packs” the insulation.
Dense packing walls is a great application of blown-in cellulose. In fact, dense packing walls results in remarkable performance, or even blowing in cellulose on a flat application is a great use as long as there are baffles installed and wind washing doesn’t occur.
At the same time, a bad use of insulation is dense pack cellulose and or fiberglass batt insulation in an unvented cathedral ceiling. Why? Where or how does the air circulate if this area has no baffles or venting? It doesn’t vent, and because there is no vapor barrier or other sealing qualities, mold may form in the area which can sometimes bleed through your ceilings and become a health hazard.
The dense pack process is usually completed by a professional, with a variable speed cellulose machine. The units Home Depot or Lowe’s let you use from the store are not variable speed, and if you aren’t careful you can blow the walls (either drywall or plaster and lap) right off the drywall screws or nails – ruining your walls, and also leaving cellulose all over your floors.
Professionals also have infrared cameras (IR) cameras to see what cavities in your house have been filled and what cavities have been missed to make sure the whole wall gets dense pack cellulose and there are no misses or insulation gaps.
Using dense pack cellulose is also great for “flash and batt” insulation. During this process, a vapor barrier of spray foam is installed on the outer wall of the house sealing off the cold from the hot; then a mesh or 3-mill plastic is applied to the studs, followed by dense pack cellulose on top of the spray foam, and finally drywall.
Dense pack cellulose is a great alternative for someone who can’t afford all spray foam, but wants at least some spray foam because of its excellent air sealing qualities. For more information, please contact me for more information or a quote.
Dr. Sprayfoam (Mark Gugino)