Insulating Walls with Dense Packed Cellulose

Dr. Energy Saver is On The Job again...this time to help a local homeowner make his home a more comfortable and energy efficient building by improving wall insulation.

This house, like many others in the U.S., had its exterior walls insulated with fiberglass batts when it was originally constructed. In this case, Larry Janesky, owner and founder of Dr. Energy Saver, demonstrates and explains why the fiberglass insulation wasn't doing a good job of insulating the wall cavity.

Using a borescope, a diagnostic device consisting of a camera attached to a long flexible tube with a lens at the end, Larry shows us the big gap between the facing of the 2-inch thick fiberglass batt and the drywall, in this 3.5-inch thick exterior wall.

Fiberglass insulation, even when properly installed, doesn't stop air flow and, in this case, the gap within the wall cavity left plenty of room for air to flow in and out of the living space. With the fiberglass insulation heat is consistently lost through the exterior walls during the winter, and gained during the summer, making this house very difficult and expensive to heat and cool.

For this home, dense packing cellulose insulation on top of the existing fiberglass insulation was the chosen method. Cellulose is an environmentally friendly insulating material made with shredded paper and also a powerful fire retardant - giving cellulose insulation one of the highest fire safety ratings among all insulation materials. The paper is treated with borate -- a harmless, antiseptic used in eye washes and similar household applications -- to inhibit mold growth and deter pests.

To install the insulation and reduce the amount of dust, powerful, high pressure blowers are used to pack the cellulose in wall cavities. To minimize disruption for the homeowner, the wall cavities are usually accessed from the outside, by drilling holes under the siding. This particular home was scheduled to get brand new siding so the holes were drilled straight through the existing cedar siding.

A surprisingly large amount of cellulose is normally used to dense pack walls, even in these walls where they were already insulated with fiberglass. From the inside of the home and during installation, Larry explains how dense packing cellulose will help stop both air flow and conductive heat transfers through the exterior walls.

With exterior walls properly insulated and air sealed, this home is now easier to heat and cool, year round - making the energy bills much more affordable. Among the many homeowners we help every day, all across the US, this is one more satisfied customer! We would love to help you too.

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