Up to 40% of your home's energy loss occurs through the attic. Hot air rises, and without adequate insulation, it escapes right through your ceiling into the attic and out through the roof. In summer, solar heat radiates through the roof and into your living space. Proper attic insulation is the single most impactful energy upgrade you can make.
How Much Insulation Do You Need?
Indiana falls in DOE Climate Zone 5, which recommends R-49 to R-60 in attics. Here's what that means in real terms:
- Blown-in cellulose: 13-16 inches for R-49
- Blown-in fiberglass: 16-20 inches for R-49
- Fiberglass batts: Multiple layers totaling 14-16 inches for R-49
Many older Indiana homes have only R-19 or less — well below current recommendations.
Air Seal First
Before adding insulation, the attic floor must be air sealed. Common leak points include:
- Around plumbing and electrical penetrations
- Recessed light fixtures (use IC-rated covers)
- The attic hatch or pull-down stairs
- Top plates of interior walls
- Around chimneys and flues (use fire-rated materials)
- Ductwork boots and connections
Air sealing alone can reduce energy loss by 10-20%.
Ventilation Matters
Proper attic ventilation prevents moisture buildup, ice dams, and premature roof deterioration. A balanced system with intake vents (soffit) and exhaust vents (ridge or roof) maintains airflow above the insulation. Never block soffit vents with insulation — use baffles to maintain the air channel.
Signs You Need More Attic Insulation
- You can see the floor joists when looking in the attic
- Existing insulation is below the top of the joists
- Rooms below the attic are noticeably hotter in summer or colder in winter
- Ice dams form on your roof in winter
- Your energy bills keep climbing
Schedule a free attic assessment and we'll measure your current R-value and recommend the best upgrade path.