This post will be published in the April 2018 issue of Doors & Hardware
As the price per square foot of real estate rises, sliding doors are becoming more popular in business, residential, and health care occupancies. While swinging doors require approximately 9 square feet of floor area to accommodate the door’s swing, almost no floor space must be dedicated to the operation of sliding doors, which run on the face of the adjacent wall or even inside of the wall (pocket doors).
Manually-operated sliding doors are not always allowed in a means of egress, since the model codes require side-hinged or pivoted swinging doors for most locations. The International Building Code (IBC) currently contains 9 exceptions where swinging doors are not required and other types of doors are allowed:
- Private garages, office areas, or factory/storage areas with an occupant load of 10 or less
- Detention areas (I-3 use group)
- Some types of patient rooms within suites in a health care facility
- Dwelling units in residential use groups R-2 and R-3
- Revolving doors complying with Section 1010.1.4.1, except in high hazard occupancies
- Special purpose horizontal sliding, accordion, or folding door assemblies – power-operated doors that are usually in the open position but may close upon fire alarm – except in high hazard occupancies
- Power-operated doors with the breakout/breakaway feature
- Bathroom doors in residential R-1 dwelling units
- Manually-operated horizontal sliding doors serving an area with an occupant load of 10 or less, except in high hazard occupancies
Item 9 addresses manually-operated horizontal sliding doors, and limits their use to doors serving an area with a calculated occupant load of 10 people or less, in any occupancy with the exception of high hazard occupancies. Many of the requirements for manually-operated sliding doors are the same as those for swinging doors, but it’s important to know where they differ:
Opening Force – Opening force for manually-operated sliding and folding doors is limited to 5 pounds of opening force, maximum. This limitation does not include the force required to release the lock or latch.
Clear Opening Width – The minimum allowable clear opening width for a sliding or folding door that is part of an accessible route is 32 inches. Projecting hardware that prevents the door from sliding completely open will affect the clear opening width.
10-inch High Flush Bottom Rail – Sliding doors are exempt from the requirement for a flush, smooth area extending from the floor to 10 inches up the face of the door. This requirement applies to the push side of manual swinging doors.
Maneuvering Clearance – The maneuvering clearance required for sliding doors is different from the amount of clearance required for swinging doors, because of the method of operation and the fact that there is no need to maneuver out of the path of the door swing. The ADA standards (free download here) include a table and graphics to illustrate the required maneuvering clearance for sliding doors, as well as folding doors and doorways without doors:
Hardware – Operable hardware on sliding doors must be operable without tight grasping, pinching, or twisting of the wrist, with a limited amount of force, and must be mounted between 34 inches and 48 inches above the floor. One releasing operation must unlatch the door for egress. In addition, the hardware must be exposed and usable from both sides when the sliding door is in the fully-open position. In the past, sliding pocket doors often had an edge pull which required dexterity to operate, and the door would slide all the way into the pocket. Most AHJs do not consider a traditional edge pull operable without tight grasping or pinching, and when the door is in the pocket, the hardware is not exposed and usable from both sides.
To comply with current accessibility requirements, sliding doors are often equipped with surface-mounted door pulls on each side of the door. These pulls prevent the door from sliding all the way into a pocket or completely out of the opening if it’s a sliding door mounted on the face of the wall. When the door is fully open or fully closed, there should be at least 1 1/2 inches of space between the door pull and the frame, as well as behind the door pull. Keep in mind that the surface-mounted hardware and required clearance will affect the clear opening width when the door is in the fully-open position. Updated pocket-door locks incorporating a retractable edge pull are available, which do not require tight grasping, pinching, or twisting of the wrist and may be acceptable to the Authority Having Jurisdiction (AHJ).
NFPA 101 – Life Safety Code
The requirements of NFPA 101 vary slightly from those of the IBC and the referenced standards, so it’s important to refer to the specifics of the codes that have been adopted in a project’s jurisdiction. Similar to the IBC, NFPA 101 requires doors serving most egress routes to be swinging doors, but includes some exceptions in the occupancy chapters. These exceptions include door assemblies meeting the required criteria in dwelling units (Chapter 24), residential board and care occupancies (Chapters 32 and 33), horizontal sliding or vertical-rolling security grilles or door assemblies (Chapters 11 through 43) and horizontal sliding doors in detention/correctional occupancies (Chapters 22 and 23). The code also addresses special-purpose horizontally sliding accordion or folding doors, vertical-rolling door assemblies, revolving doors, and existing fusible link operated fire doors (Chapters 39, 40, and 42).
Horizontal-sliding doors are allowed by NFPA 101 unless prohibited by the occupancy chapters, as long as the door is not serving an area with a calculated occupant load of 10 people or more. The room served by the sliding door must not have high hazard contents, must be readily operable from either side without special knowledge or effort, and the force required to operate the door must not be greater than 30 lbf to set the door in motion and not more than 15 lbf to open the door to the required width or to close the door. The code includes additional requirements for sliding fire doors and sliding doors that are required to be self-latching, such as doors in a health care corridor.