02/02/2026
The Invisible Enemy: Why Container Homes "Sweat."
If you build a normal house, the walls breathe. If you build a container home, the walls sweat.
The top photo shows the only guaranteed cure: Closed Cell Spray Foam.
The Science: Metal conducts cold. When warm air from your shower or breath hits that cold steel, it turns into water (condensation).
The Risk: Look at the bottom photo (Rockwool Batts). It looks neat, but if you don't install a perfect v***r barrier over that wool, moisture will get behind it. The result? Mold growing secretly behind your walls for years.
The Solution: Spray foam (Top) bonds chemically to the steel. It leaves zero gap for air or water. It is a moisture barrier, insulation, and structural glue all in one.
It’s messy and expensive, but it’s the only way to sleep soundly knowing your walls aren't crying.