walls have no insulation

[msimerson]

information

• walls have 3.5" cavities
• INSULATION

procure materials

• buy 3" polyiso foam board insulation (buy foam board insulation #37)
  • wrap foam board in Tyvek to protect it ($160)
• buy furring strips for nailers
  • (314) 8' long 1x3 or 1x4
  • (20) 3/4" 4x8' plywood
• buy screws, qty estimate: 1548
  • 9" Wind Lock SIP Screws, $0.81 ea.
  • 9" Dekfast SIP screws, $0.35 ea.
  • Trufast
  • 9" Headlok Panel screws, $0.56 ea.
• buy new windows (windows are single pane aluminum framed #8)
• buy house wrap: (2) 9'x150' rolls, $217 @ Lowes
• have z-channel fabricated (300')
• buy insect screening

insulate cavity

• choose type (see options) (choice: dense-pack cellulose)
• hire contractor to dense pack the walls
  • get 3 bids
    • Arrow Insulation
    • Classic Pest Control & Insulation
  • select contractor
  • schedule job
• inspect & verify

walls todo

• house wall north insulate house wall north #93
• house wall east insulate house wall east #94
• house wall south insulate house wall south #95
• house wall west insulate house wall west #96
• great room wall east insulate great room east wall #92
• great room wall west insulate great room west wall #97
• garage walls garage is not insulated #4

wall cavity options

type	R-value	Material	Installed
dense-packed cellulose	13	$950	$2,500
closed cell spray foam	24	$7,000

References

• Department of Energy recommends:
  • "Uninsulated wood-frame wall: Drill holes in the sheathing and blow insulation into the empty wall cavity before installing the new siding, and add R5 or R6 insulative wall sheathing beneath the new siding"
• How to Install Rigid Foam Sheeting
• How to Install Rigid Foam Insulation Outside a House
• no siding is waterproof
  • provide paths for water to drain down and out
• Avoid reverse laps - higher layers always overlap lower layers

[msimerson]

note: since I added R-36 to the exterior of the walls (outside the sheathing), the additional insulation possible in the stud cavities turned out not be necessary. It could still be done, but the ROI is vanishingly low.