J-Strap Heavy Duty Bifold Barn Door Hardware Kit | 4-Door Biparting

The J-strap heavy duty 4-door biparting bifold kit folds four panels accordion-style along a wall-mounted track, with two panels folding and stacking to each side of the opening — built for solid-wood panels, oversized doors, and installations where standard duty hardware isn't enough. J-strap hangers mount to the front face of the outer panel on each side, carrying the familiar J-strap aesthetic across the full installation. When open, the entire span clears symmetrically with 5 in of folded hardware on each side.

This is a Goldberg Brothers heavy duty kit, made to order in Colorado with a limited lifetime warranty. Available in all 17 Goldberg Brothers powder coat finishes. Two 7 in pull handles are included — one per side. Ships in 10–15 business days. Total system weight capacity is 800 lbs across all four panels.

Biparting requires wall clearance on both sides — for a fully clear opening, only 5 in of clear wall is needed on each side. If clearance only exists on one side, see our 4-door one-way kits instead. For lighter or thinner panels within the standard duty range, standard duty 4-door biparting hardware is less expensive and fully sufficient.