Handrail: Difference between revisions
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Handrails and railings are to support a continuous load of 50 plf(75kg-m) or a concentrated load of 200 pounds (90 kg). While most steel and aluminum members are adequate to accommodate those loads, decorative wood balusters generally fail under the required loads. |
Handrails and railings are to support a continuous load of 50 plf(75kg-m) or a concentrated load of 200 pounds (90 kg). While most steel and aluminum members are adequate to accommodate those loads, decorative wood balusters generally fail under the required loads. |
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== Types of Handrails == |
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Handrails are typically available “plowed” and “un-plowed” or “flat bottomed”. A plowed handrail has its bottom grooved or “plowed” to receive a square topped baluster to simplify the installation process. In order to ensure a flat surface for a plowed handrail, a “fillit” is then cut and fitted between the balusters to “fill” the groove. |
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== See also == |
== See also == |
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Revision as of 17:54, 6 September 2010
 | This article needs additional citations for verification. (December 2007) |
A handrail is a rail that is designed to be grasped by the hand so as to provide stability or support.[1] Handrails are commonly used while ascending or descending stairways and escalators in order to prevent injurious falls. Other applications include bathroom handrails—which help to prevent falls on slippery, wet floors—and barres, which serve as training aids for ballet dancers. Handrails are typically supported by posts or mounted directly to walls.
Handrail dimensions (USA)
Various model codes -- The International Code Council (ICC) and National Fire Protection Association (NFPA)-- and accessibility standards -- ANSI A117.1 and the Americans With Disabilities Act Accessibility Guidelines (ADAAG) -- refer to handrail dimensions. Current versions of these codes and standards now agree that handrail is defined as either a circular cross section with an outside diameter of 1-1/4" (32 mm) minimum and 2" (51 mm) maximum or a non-circular cross section with a perimeter dimension of 4" (100 mm) minimum and 6-1/4" (160 mm) maximum and a cross section dimension of 2-1/4" (57 mm) maximum. In addition, the International Residential Code (IRC) includes a definition of a "Type II" handrail that allows for handrail with a perimeter dimension greater than 6-1/4" (160 mm).
The IRC and residential portion of the 2009 IBC define Type II handrail as follows:
Type II. Handrails with a perimeter greater than 6-1/4 inches (160 mm) shall provide a graspable finger recess area on both sides of the profile. The finger recess shall begin within a distance of 3/4 inch (19 mm) measured vertically from the tallest portion of the profile and achieve a depth of at least 5/16 inch (8 mm) within 7/8 inch (22 mm) below the widest portion of the profile. This required depth shall continue for at least 3/8 inch (10mm) to a level that is not less than 1-3/4 inches (45 mm) below the tallest portion of the profile. The minimum width of the handrail above the recess shall be 1-1/4 inches (32 mm) to a maximum of 2-3/4 inches (70 mm). Edges shall have a minimum radius of 0.01 inch (0.25 mm).[1]
Handrails are located at a height between 34" (864 mm) and 38" (965 mm). In areas where children are the principal users of a building or facility, the 2004 ADAAG recommends that a second set of handrails at a maximum height of 28" (711 mm) measured to the top of the gripping surface from the ramp surface or stair nosing can assist in preventing accidents.
Handrail clearance (USA)
The distance between the wall and handrail gripping surface is also governed by local code with the most common requirement being 1-1/2" (38 mm) minimum. The National Fire Protection Agency (NFPA) requires that the distance between the wall and handrail be a minimum of 2-1/4" (57 mm).
The 1992 Americans With Disabilities Act Accessibility Guidelines (ADAAG) stated that there was to be an absolute dimension of 1-1/2" between a handrail and a wall. This was actually a "grab bar" dimension which was part of the 1986 ANSI A117.1. ANSI changed the notation to 1-1/2" minimum in 1990. This was not corrected in ADAAG until 2004 which now calls for a 1-1/2" (38 mm) clearance.
Codes also generally require that there be a 1-1/2" clearance between the underside of the handrail and any obstruction -- including the horizontal bracket arm. There is an allowance however for variations in the handrail size -- for every 1/2" of additional perimeter dimension over 4", 1/8" may be subtracted from the clearance requirement.
Handrail strength (USA)
Handrails and railings are to support a continuous load of 50 plf(75kg-m) or a concentrated load of 200 pounds (90 kg). While most steel and aluminum members are adequate to accommodate those loads, decorative wood balusters generally fail under the required loads.
Types of Handrails
Handrails are typically available “plowed” and “un-plowed” or “flat bottomed”. A plowed handrail has its bottom grooved or “plowed” to receive a square topped baluster to simplify the installation process. In order to ensure a flat surface for a plowed handrail, a “fillit” is then cut and fitted between the balusters to “fill” the groove.
See also
References
- ^ "Dictionary.com". Retrieved 2007-06-26.
External links
