Attic Insulation & Air Sealing in Dickson, TN

Attic insulation and air sealing do most of the work of keeping a Dickson house cool. On a July afternoon, an attic can get far hotter than the outdoor air. That heat soaks down through thin insulation into the rooms below, and warm air leaks in through gaps around lights, pipes, the hatch and the tops of walls. If ductwork runs through the attic, it heats the cool air before it reaches the vents.

Seal, then insulate

We seal the bypasses in the attic floor first, weatherstrip and insulate the hatch and put baffles at the eaves so soffit vents stay open. Then we blow loose fill across the attic to depth. HomeGuide rates cellulose at R-3.1 to R-3.8 per inch and blown fiberglass at R-2.2 to R-2.9.

How deep

The Insulation Institute's summary of Tennessee's 2018-based code lists R-38 for ceilings in Climate Zone 4, which includes Dickson County. That is roughly 10 to 12 inches of cellulose. Many older attics in the area have half that or less.

When to foam the roof deck instead

If the HVAC unit and ducts are in the attic, an alternative is to spray open-cell foam under the roof deck and seal the attic's vents. The attic then stays close to indoor temperature, and the ducts stop losing cool air. It costs more than blown-in, and we recommend it only when equipment or ductwork is up there.