We quickly identified the basement as a major contributor to their air quality woes. The rubble foundation offered myriad entry points for mice, and the dirt floor admitted soil gases. In addition, a great deal of old wood and cardboard stored in the basement was rotting and moldy. Because the basement wasn't sealed from the rest of the house, contaminants that originated there eventually permeated the entire house.
The basement was also a major factor in the homeowners' thermal discomfort. Cold wintertime air poured into the space and-just like the basement contaminants-circulated throughout the entire house. The house also lacked wall and attic insulation, and the windows were incredibly leaky.
To solve these problems we focused on the building envelope, creating a true barrier between outside and inside. In the basement, we excavated several inches of dirt and installed a perimeter drain and sump pump. Then, we laid down rodent-blocking mesh screening, and blew in foam insulation along the walls and the floor. Finally we installed a concrete slab on top of the foam.
We addressed the remaining portions of the envelope by filling the roof rafters with foam insulation, blowing cellulose insulation into the walls, and replacing the leaky single-paned windows with tighter double-paned ones.
The basement is now clean and dry, and the entire house is much more comfortable. The homeowners no longer have to crank the heat to stay warm, and the mice and other sources of poor air quality have been eliminated. The homeowners are also pleasantly surprised by how much quieter their house is: the added insulation dampens the street noise of their lively neighborhood, and the windows no longer rattle when the wind blows.
All in all, it's an excellent outcome, one that should allow the homeowners to remain in the home and the neighborhood that they love for many years to come-and to really enjoy their time there.