Cellulose Insulated Attic Makes For a Cozy Home
'The weather outside is frightful, But the fire is so delightful, And since we've no place to go, Let It Snow! Let It Snow! Let It Snow!' Snow is falling and I am nearly giddy. Why? We've just finished sealing and insulating the attic with 15 inches of recycled cellulose insulation and our home is now quite cozy and snug. Let It Snow!
Step one was to have a new 'cool roof' installed. With a good roof over our heads I installed air chutes (a.k.a. soffit baffles or insulation trays) to vent air from the eaves up to the ridge vent. My next step was to seal over the central hall which had an uninsulated heat duct and two interior walls with gaps in the drywall which allowed cold air to siphon heat out of the house (Thermal Bypass). After many dusty trips into the attic with carefully cut drywall and cans of expanding spray foam I sealed over the walls and heating duct. Then our local insulation specialist came with a truck filled with bales of recycled cellulose insulation, an industrial blower system and many years of experience in installing insulation.
We now have an R-49 value (per the DOE recommendation) of borate-only, cellulose insulation over the living space of our home. Why borate-only? Some brands of cellulose insulation are treated with sulfates, which create sulfuric acid when combined with moisture (i.e. high humidity or a roof leak). Sulfuric acid corrodes metals (especially copper wires and pipes) and has other health concerns. Fortunately our contractor uses the borate-only insulation as the local DIY centers only sell cellulose treated with sulfates!
It's only been a few days, so we can't compare heating bills yet. But, we have noticed the furnace runs MUCH LESS often. Also, the house is more comfortable even at the same thermostat setting. The interior air temperature feels more even and the hall walls are warmer. The next step will be to apply for a Home Insulation Rebate from the local gas company. A cozier home, lower utility bills and money back from the utility - what a warm and wonderful thought for the winter!
More Info:
Wikipedia - Home Insulation
Wikipedia - Cellulose Insulation
DOE - Home Insulation Fact Sheets
DOE - Insulation R-Value Recommendations
DOE - ZIP-Code Insulation Program
ENERGY STAR Thermal Bypass Checklist
Corrosion of Metals Under Thermal Insulation (Sulfates in Cellulose Insulation)
