Custom bi-fold steel doors
Our bi fold and multi fold steel doors are engineered to create expansive openings, maximize natural light, and enhance indoor-outdoor living. Designed for modern architecture, they combine smooth operation with structural strength.
We have a wide variety of configurations for your folding door. We can do it with odd panels, using the last one as a swing active door, as well as even panels. In this way we can adapt to the designs of our clients according to the style they want to achieve and functionality.
Benefits:
- Custom design
- Variety of settings
- Thermal performance
- High-tech and quality mechanisms
- Durability due to hot-dip galvanized steel treatment
- Low maintenance
- Quick Install
- Maximization of light input
- Slim profiles
Available Lines
How a Bi-Fold Steel Door Works
A bi-fold door has panels that fold accordion-style against each other as they open, moving outward or inward and to the side. A 4-panel system opens by folding the first two panels against the second two, creating two stacked pairs at one or both ends of the opening.
The result is what makes bi-folds worth the engineering: essentially the entire opening width becomes clear, with minimal panel stack at the sides. HERRERO builds configurations from 2 to 8 or more panels, spanning openings of 30 feet and beyond.
Bi-Fold or Sliding?
Both systems open widths no swinging door can match, but they scale differently. Sliding systems work well from 6 to 20 feet or more, though at very large widths some panels stay fixed while others pass in front of them — the opening never becomes fully clear.
Bi-folds handle 20 feet and beyond with every panel moving and the whole opening clear when folded back. The trade-off is mechanical: more hinges, more moving parts, and more to keep aligned over decades of use. The full comparison is here.
Why Steel for a Folding System
Folding panels are handled constantly, and every hinge is a point where a weaker frame eventually racks out of alignment. Steel carries roughly three times the tensile strength of aluminum, holding panel geometry across thousands of cycles while keeping sightlines narrow.
Every unit is hot-dip galvanized as standard — the hinges and hardware of a folding system are exposed to the same salt air and humidity as the panels — then finished in powder coat from the full RAL palette. See finish options.
Lines and Glazing
Bi-fold systems are available in SLIM LINE for the narrowest sightlines and in the thermally broken ECO-SKY line where the envelope calculation requires it. Because a bi-fold is mostly glass, the glazing package drives Title 24 compliance more than on any other opening. Review glass options; NFRC ratings and labels supplied for submittal.
What We Need to Quote
Rough opening dimensions; panel count and fold direction; wall assembly type; the floor condition at the track; glass performance requirements; finish color and type; and hardware preferences. For projects under $20,000 we typically respond within 5–7 business days; $20,000 to $100,000 takes 7–10 business days. See the full ordering process.
HERRERO Steel Doors & Windows
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