Insulating walls in a home or building is critical to achieving high energy efficiency. A big factor in the effectiveness is how well the wall cavity is sealed by the insulation. Fiberglass batts do not create an effective seal. Over the past few years foam insulation has gained popularity for its ability to seal wall cavities. But cellulose insulation is just as effective while offering other advantages.
Cellulose insulation completely seals wall cavities when installed by a professional insulation contractor experienced with the product. It is blown in with a machine that fills the entire space including around and behind plumbing and electrical elements.
The insulation is actually over-filled and becomes dense packed by the blower. After the wall is completely filled the installer uses a tool to scrape off the overfill creating a finished area flush with the framing members.
The finished installation gives a tight seal within the wall cavity and is as effective as foam with similar R-Values.
The main differences are cost and environmental benefits. Foam is more expensive than cellulose insulation. It varies by location similar to other building products, but generally there is a savings with cellulose compared to foam insulation.
In addition, foam is a petroleum based product. It requires up to 60 times more embodied energy to produce than cellulose insulation. Cellulose insulation is also made with 80% or more recycled waste paper – most of it in the form of post-consumer material. Foam has no recycled content.
So, with cellulose insulation, consumers can achieve similar R-Values with an effective seal against air infiltration at a lower cost while still achieving high energy efficiency. They also get the satisfaction of doing it without the environmental impacts and actually making a difference in the effort to control climate change.