Red iron metal building, project profile
This one’s a quick walkthrough of a recent metal-building insulation job, useful if you’re considering closed-cell SPF on a similar structure.
The building
Red-iron commercial metal building, roughly 5,000 square feet, intended as a workshop and storage space. Single-skin metal panels on the walls and roof, no existing insulation. The owner had already lost some stored electronics to condensation drip and was about to lose more.
The problem
Single-skin metal panels in SWFL are condensation factories. The diurnal temperature swing, combined with high humidity, means the underside of the metal is constantly hitting dew point. Without insulation, that water beads up and drips onto everything below. Over a season, you get rust, mold, and ruined inventory.
The work
We applied closed-cell spray polyurethane foam directly to the underside of the roof deck and the inside of the wall panels. Application was staged so we could move the owner’s stored items in sections rather than emptying the whole building.
Closed-cell foam was the right product here because it:
- Air-seals the envelope. No gaps, no penetrations.
- Vapor-barriers in one step. No separate poly sheet needed.
- Adds rigidity to the panel-and-purlin system.
- Won’t sag off the underside of a roof deck the way batt insulation does over time.
The result
- Condensation gone. The underside of the roof is no longer hitting dew point on the interior surface.
- Internal temperature swings dropped noticeably; the building is usable year-round without large HVAC.
- Stored equipment is dry.
- Visible foam finish is clean and even, with no shadowing or pull-back.
When closed-cell SPF makes sense
For metal buildings in SWFL, closed-cell is almost always the right answer. It’s more expensive per inch than open-cell or fiberglass, but the combination of vapor barrier, air seal, and high R-value-per-inch is exactly what a sweating metal building needs.