Uploaded June 2026 | Updated September 2026, 2 weeks ago
WE CAUGHT THEM.
For years we've been told the answer is simple:
➡️ Add more insulation.
➡️ Increase the R-value.
➡️ Vent the attic.
➡️ Everything will be better.
But what happens when the insulation itself becomes part of the moisture problem?
I recently reviewed a report by professional engineer Kent Browning that examined vented attics in hot, humid climates. The findings are hard to ignore.
The report documents that fibrous loose-fill insulation can absorb and store moisture, then release that moisture back into the attic as conditions change throughout the day. In some cases, the amount of water stored in the insulation was significant enough to meaningfully affect attic humidity levels.
Even more interesting, the report notes that as insulation levels increased from R-19 to R-30, R-38 and R-49, moisture and mold concerns became more common in vented attic assemblies.
Think about that.
The industry's answer for decades has been:
"Just keep adding more insulation."
But if the insulation is storing moisture, shouldn't that be part of the conversation?
This isn't about attacking insulation.
This isn't about attacking people.
This is about asking a very simple question:
What happens when the theory doesn't match what is happening in the real world?
The report's conclusion is blunt:
"The only good attic ventilation is no ventilation."
Whether you agree or disagree with that statement, the data deserves to be discussed.
For years I've argued that building performance is about more than a laboratory R-value. Air movement matters. Moisture movement matters. Assembly design matters.
A building doesn't care what the marketing brochure says.
It only responds to physics.
Watch the video and decide for yourself.
Is it time to start asking tougher questions about how we insulate attics?
#SprayFoam #BuildingScience #AtticVentilation #Insulation #Construction #BuildingPerformance #EnergyEfficiency #HomeBuilding #Roofing #HVAC #ThinkSprayFoam #SprayJones
WE CAUGHT THEM.
For years we've been told the answer is simple:
➡️ Add more insulation.
➡️ Increase the R-value.
➡️ Vent the attic.
➡️ Everything will be better.
But what happens when the insulation itself becomes part of the moisture problem?
I recently reviewed a report by professional engineer Kent Browning that examined vented attics in hot, humid climates. The findings are hard to ignore.
The report documents that fibrous loose-fill insulation can absorb and store moisture, then release that moisture back into the attic as conditions change throughout the day. In some cases, the amount of water stored in the insulation was significant enough to meaningfully affect attic humidity levels.
Even more interesting, the report notes that as insulation levels increased from R-19 to R-30, R-38 and R-49, moisture and mold concerns became more common in vented attic assemblies.
Think about that.
The industry's answer for decades has been:
"Just keep adding more insulation."
But if the insulation is storing moisture, shouldn't that be part of the conversation?
This isn't about attacking insulation.
This isn't about attacking people.
This is about asking a very simple question:
What happens when the theory doesn't match what is happening in the real world?
The report's conclusion is blunt:
"The only good attic ventilation is no ventilation."
Whether you agree or disagree with that statement, the data deserves to be discussed.
For years I've argued that building performance is about more than a laboratory R-value. Air movement matters. Moisture movement matters. Assembly design matters.
A building doesn't care what the marketing brochure says.
It only responds to physics.
Watch the video and decide for yourself.
Is it time to start asking tougher questions about how we insulate attics?
#SprayFoam #BuildingScience #AtticVentilation #Insulation #Construction #BuildingPerformance #EnergyEfficiency #HomeBuilding #Roofing #HVAC #ThinkSprayFoam #SprayJones
