- Client
- A material handling integrator building out a leased distribution facility in Fort Worth, Texas
- Area separated
- 250,000 square feet conditioned, inside a single open warehouse volume
- Challenge
- A Type IIB noncombustibility requirement the product category cannot meet, against a roof structure with no spare load capacity
A Fort Worth distribution facility needed 250,000 square feet of temperature-controlled storage inside a building that had none. The space existed — it was one open volume with no interior partition, and conditioning the whole building to hold storage temperature was never economically serious.
Steel Guard Safety was brought in by Top Shelf Integrated Solutions, the Columbus, Ohio material handling integrator managing the project. The scope looked straightforward: an insulated demising curtain, 600 feet long, floor to roof deck, dividing the building in two.
Two constraints turned it into an engineering problem, and each one made the other harder to solve.
The building wouldn’t hold it
The roof structure had almost no spare load capacity. The curtain as originally designed came to 18 pounds per linear foot. The existing bar joist could carry 6.
The conventional answer is steel. The first structural solution called for welded reinforcement extending 24 feet from the girder — a scope that adds cost, adds schedule, and puts a welder overhead in a building the tenant is trying to move into.
Moving the panel load off the roof structure brought every valance section inside the joist’s unreinforced capacity and removed the structural steel scope from the job.
The code wouldn’t allow it
Running in parallel, the plans review raised a requirement the insulated curtain industry is not built to satisfy.
The building is Type IIB construction. Under the 2021 IBC, materials in the partition had to be noncombustible — and the reviewer held that the curtain being non-structural made no difference to that requirement.
The insulation originally specified was a reflective laminate. Its manufacturer confirmed directly that ASTM E136 could not be run on it at all. E136 — the vertical tube furnace test at 750°C that the code references to classify a material as noncombustible — excludes laminated and coated materials by its own scope, and excludes materials that soften or melt under test.
That is not a defect in one product. It is a structural fact about the category. Conventional insulated curtains pair a coated facing with a laminated core, so the finished assembly cannot carry an E136 classification.
The reviewer’s requirement was specific. Absent E136, the submission needed documentation of ASTM E2652 compliance evaluated against E136’s acceptance criteria, or an ICC‑ES report confirming noncombustibility for Type IIB construction.
What the submission had to clear
- Noncombustible materials under 2021 IBC 602.2, Type IIB construction
- ASTM E136, or E2652 evaluated against E136 acceptance criteria, or an ICC‑ES report
- Assembly weight within 6 lb per linear foot, unreinforced
- R‑9 minimum thermal performance across the partition
- No delay to the tenant’s move-in schedule
An argument that the material qualified under the thermal insulation allowance in IBC 603.1 did not carry. To keep the rest of the project moving, the project architect pulled the curtain out of the active permit and resubmitted it separately.
What we did
We replaced the insulation rather than the design intent.
Working through our materials supply chain, we sourced a Johns Manville insulation at 2.8 ounces per square foot delivering R‑10 on its own — R‑11 in the finished assembly with the vinyl and air gap — carrying the noncombustibility documentation the review required. The material was run at the JM plant, laminated by a converting partner, and delivered to our floor in South Holland, Illinois.
Because we manufacture in-house, the substitution was a production decision rather than a supply chain negotiation. We committed the mill order on a verbal approval to protect the schedule.
The lighter core then made the structural fix possible. Instead of hanging the assembly from the truss, we moved the main panel load to the floor and the building columns: 3/8″ galvanized aircraft cable running through the panel grommets between column-mounted brackets, with a second cable at mid-height holding the panels square and plumb. Only the valance remained on the truss.
The truss reinforcement scope was eliminated. No structural steel welding was required.
Specifications
| Area separated | 250,000 sq ft conditioned |
|---|---|
| Configuration | Insulated demising curtain, 600 linear ft |
| Height | 36’‑9″ at exterior walls rising to ~43′ at center columns |
| Main panels | 114 at 32.5′ × 5′; 6 at 14.5′ × 5′ |
| Valance | 122 numbered sections (61 per half), 5’‑5″ to 12’‑5″, cut to follow roof pitch |
| Facing | 18 oz vinyl, white |
| Insulation | Johns Manville, 2.8 oz/sq ft, R‑10 |
| Assembly R‑value | R‑11 with vinyl and air gap |
| Suspension | 3/8″ galvanized aircraft cable, 14,400 lb break strength; column-mounted brackets |
| Load path | Floor and building columns; valance only on truss |
| Fabric | ~6,536 yards |
| Access | Strip curtain door openings |
Results
- 250,000 sq ft separated for temperature-controlled storage without conditioning the full building
- Curtain materials approved on resubmission after the original insulation was rejected
- Truss reinforcement eliminated — no welding, no added structural scope
- Replacement insulation sourced, laminated, and into production within roughly three weeks of the rejection
- Panels pre-numbered by face and sequence, valance sections cut to the roof profile before shipment
- Partition is fully relocatable if the tenant’s layout or contract changes
Why it matters
Demising curtains get specified on speed and cost against hard-wall construction. This project added two constraints most suppliers can’t clear at the same time: a noncombustibility requirement written for permanent construction, and an existing roof structure with no spare capacity.
Clearing both took a manufacturer that controls its own material sourcing and fabrication — where changing an insulation core is a decision made on our own floor, and where the weight consequences of that change can be engineered back out of the design in the same week.
Facing a noncombustibility requirement or a truss capacity limit?
Send us the construction type, the joist capacity, and the temperature separation you need. We’ll tell you what’s possible before it becomes a schedule problem.
About Steel Guard Safety. Steel Guard Safety manufactures industrial curtain walls, insulated partitions, and safety enclosures at its 17,000 sq ft facility in South Holland, Illinois. A U.S. manufacturer with a 100-year family heritage, Steel Guard fabricates in-house and ships more than 4,000 orders a year.
