Does a Wall in Alaska Need a Vapor Barrier?
Yes. Every one of Alaska’s 27 counties sits in IECC climate zone 5C, 6A, 7, or 8, and none of those reach the zone 1, 2, or 3 exception written into the…
Does a Wall in Alabama Need a Vapor Barrier?
No. Alabama’s 67 counties sit in IECC Climate Zones 2A and 3A, and the 2021 International Residential Code exempts Zones 1, 2 and 3 from the interior…
When Insulation Needs Replacing, and When It Does Not
Insulation almost never needs full replacement just because it’s old. What decides the question is condition, not calendar age: whether the material got…
Which Insulation Material Goes Where
Fiberglass batts, blown cellulose, spray foam, rigid foam board, and mineral wool are not competing for the same job.
Spray Foam: What It Solves and What It Commits You To
Spray foam insulation does two jobs that other materials split between them: it fills the cavity, and it seals the air leaks inside that cavity, in one…
Insulation for Sound: A Different Job Entirely
Stuffing a wall cavity with fiberglass or mineral wool will not turn a noisy room quiet.
R-Value: What the Number on the Packet Measures
The number on an insulation package, the R-value, measures how well that material resists the flow of heat moving through it.
Rigid Foam Board: The Layer That Breaks the Bridge
Rigid foam board insulation works by covering the wood framing itself, not just filling the cavities between the studs.
Radiant Barriers: A Hot-Climate Tool, Not an Insulator
A radiant barrier reflects radiant heat instead of resisting it. That single distinction explains almost everything about how it performs, and why it…
Insulating an Older House Without Making It Damp
The safe path through this is simple to say and easy to skip: keep the house’s original drying route working, air seal before adding insulation, and…