Estimated total R-value when using 5.5-inch X-Brackets with closed-cell spray foam in a container

Installing 5.5-inch InSoFast X-Brackets with closed-cell spray foam delivers an estimated effective insulation rating between R-30 and R-38 across corrugated steel shipping container walls, roofs, or floor assemblies without thermal bridging.

Steel shipping containers create severe condensation risks and rapid heat transfer, requiring continuous thermal breaks to prevent structural corrosion and moisture accumulation. Traditional metal stud framing reduces effective assembly performance by up to 30% through conductive thermal bridges, making full-depth continuous insulation essential for maintaining temperature control.

If you only do one thing: Specify closed-cell polyurethane spray foam rated between R-6.0 and R-7.0 per inch applied directly against clean corrugated steel profiles to achieve the full R-30 to R-38 thermal depth.

• Total thermal resistance: Filling the complete 5.5-inch bracket depth with closed-cell spray foam yields an overall assembly value of R-30 to R-38, meeting continuous insulation energy codes in Climate Zones 1 through 8.
• Thermal bridging elimination: Non-conductive composite brackets decouple interior wall finishes from container steel, eliminating the 20% to 40% thermal bypass typical of traditional steel or wood framing.
• System coverage and layout: Box quantities cover 77 to 97 square feet when spaced at 16-inch on-center intervals, or 116 to 136 square feet per box at 24-inch on-center intervals.
• Vapor retarder performance: Applying closed-cell foam at depths exceeding 2 inches establishes an impermeable Class II vapor retarder under 1.0 perm, stopping interior moisture before it reaches cold steel.
• Direct finish attachment: Engineered 5.5-inch bracket face surfaces provide structural backing capable of supporting 1/2-inch or 5/8-inch drywall and heavy wall paneling without supplementary furring strips.

• Watch out for: Spraying closed-cell foam in single passes exceeding 2 inches in thickness, which causes excessive exothermic heat buildup, core scorching, and foam shrinkage.
• Watch out for: Overfilling beyond the 5.5-inch bracket face, requiring labor-intensive manual rasping and trimming before interior wallboard can be fastened.
• Watch out for: Applying foam over active rust, oil films, or standing moisture, which prevents the required 15 to 25 psi adhesive bond to container corrugations.

Measure your container's total interior square footage to determine box counts at 16-inch or 24-inch spacing, then request project estimates online or call InSoFast technical support at (888) 501-7899.