Bifold door
A folding door made of panels hinged together, common on closets. The zigzag shows the panels folding as the door opens.
How to read it
A US patent for bifold door hardware (US 10,794,108) describes these as vertically hung, track-guided, folding doors of the type used for closets. Each door is two half-doors joined by hinges, and the panels fold up in pairs and stack against the edges of the opening when it opens. The zigzag in the plan is that fold, following the rule in the Army's print-reading manual that a symbol shows how the feature moves in plan (TM 5-704).
Also searched as: closet door symbol, folding door.
This explains what a symbol represents on a drawing. Conventions vary between firms and standards, and a drawing's own legend takes precedence.
Read next
- Next in Blueprint symbolsFixed windowA window that doesn't open. It is drawn as a plain break in the wall, with no swing or sliding sash.
- The same shape in Welding symbolsBevel groove weldAn upright and a slanted line on the reference line: a bevel groove weld, where only one member's edge is beveled.
More blueprint symbols
The same shape elsewhere
Browse symbols drawn with lines.
Sources
- Bi-fold door pin brace, US 10,794,108 B1, United States Patent and Trademark Office (full text via Google Patents), background
- Construction Print Reading in the Field, TM 5-704 / AFM 85-27, Departments of the Army and the Air Force, para. 2-2a
- Reading Architects' Blueprints, William S. Lowndes, 1922, International Textbook Company, Scranton (Internet Archive), §5, art. 108
- Military Standard: Architectural Symbols (MIL-STD-14A), MIL-STD-14A, 3 September 1954, US Department of Defense (scan hosted by EverySpec), §5.1 (continued)
- Engineering Aid 3 (NAVEDTRA 14069), Nonresident training course, April 1995, Naval Education and Training Command (copy hosted by Navy Tribe), Ch. 6, interior doors
Researched, edited and approved by Rory Hansen before publishing. Last reviewed September 24, 2026. How we research
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