What Homeowners in Zone 4 Should Watch For
In Climate Zone 4, the main attic risk is drafts and uneven room temperatures. Reach the retrofit target without leaving bypasses that undermine performance.
Recommended Attic Upgrade Strategy
Most homeowners in this zone should treat attic upgrades as a combination of air sealing, insulation depth, and consistent coverage. Hitting the nominal R-value target is not enough if bypasses, hatch leaks, or wind washing are still present.
Good Material Fits for Zone 4
- blown-in cellulose
- rockwool
- fiberglass with disciplined air sealing
Attic Checklist Before You Buy More Insulation
- Inspect attic hatch insulation and weatherstripping
- Cover low-depth spots around eaves and soffits
- Make sure old insulation is dry before adding more