Guard rail & handrail strength requirements & strength testing requirements specified in various building codes & standards. This article provides details about standards, requirements & testing procedures for handrailings & guardrailings in or on the exterior of buildings.

Our page top photo shows an odd guardrail along a tiny walking space - the DIY owner-installer never considered that someone (a house painter) might actually need the railing to be secure and functional. The result was a serious injury.

Guardrail, Stair Rail & Handrail Strength Requirements - the 200 pound load criterion & others

Definition of handrail & guardrail strength requirements along with appropriate building code citations. Types of guardrailings vs. strength requirements for cable, glass, plastic, wood & other guardrail types.

In their 2001 study of an unsafe wooden deck railing assembly, Barnett and Switalski point out that the first American safety standard to address railing design (except residential railings) was the American Standard Safety Code for Floor and Wall Openings, Railings and Toe Boards, ASA A12-1932. [45][46]

That study and other sources cite an array of standards that address some but most-likely not all of the considerations in building or testing a safe guardrail or deck rail system.

By 1967 in the U.S. there were national standards for railings and guardrails, and by 1973 ANSI standards were available.

The railing must be strong enough to resist horizontal loads from people leaning on it.

Article Contents

• GUARDRAIL STRENGTH SUMMARY
• GUARDRAIL STRENGTH TEST STANDARDS
• GUARDRAIL STRENGTH TESTING IN PLACE
• GUARDRAIL OSHA FALL PROTECTION
• GUARDRAILS, GLASS SYSTEMS
• GUARDRAILS, METAL SYSTEMS
• GUARDRAILS, PLASTIC SYSTEMS
• GUARDRAILS, WOOD & COMPOSITE SYSTEMS
• GUARDRAIL FAILURE STUDIES
• GUARDRAIL POST CODES & SPECS
• CABLE RAILINGS & GUARDRAILS - separate article

200 Pound Concentrated Load, 50 Pound PSF Load Guardrail Strength Requirements

The 2000 IRC (IRC Table R301.5) and other typical building codes requires that a guardrail or a handrail be able to resist a 200-pound concentrated load applied along the top in any direction, while some local codes still in effect specify a smaller load of 20 pounds per linear foot.

After an above-ground swimming pool was removed, the owners continued to use the deck in our photo (left). Deer netting was installed across the open edge of the deck - and it worked fine until someone fell thorough it. The torn remains of the deer netting can be seen on the left side of this photograph.

Continuing from from Best Practices Guide to Residential Construction (Steve Bliss, J Wiley & Sons) :

Under the IRC, the infill or balusters must resist a concentrated horizontal load of 50 pounds applied to a square foot area. The baluster requirement is easily met with standard fastening techniques, but meeting the IRC guardrail requirement is difficult without adding steel hardware. The majority of residential decks, which rely on notched posts lag-screwed into the band joist, do not meet the 200-pound requirement.

Watch out: at least some of the standards & procedures specified for testing handrailing & guardrailing or stair rail strength focus on static strength testing. Dynamic testing such as the forces exerted when a person is falling and grabs onto a railing may be important for further consideration.

An additional warning from ASTM explains how you can or cannot use the standards summaries listed here and in further detail at the ASTM website. Quoting:

This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date. [1]

Guardrailing strength specifications & testing procedures & standards

General references

• ASTM F 1679 Standard Test Method for Using a Variable Incidence Tribometer (VIT)
• ASTM E 2126 Standard Test Methods for Cyclic (Reversed) Load Test for Shear Resistance of Vertical Elements of the Lateral Force Resisting Systems for Buildings
• Manual for the Inspection of Residential Wood Decks and Balconies, by Cheryl Anderson, Frank Woeste (Forest Products Society), & Joseph Loferski, October 2003, ISBN-13: 978-1892529343, [Developed by wood science researchers at Virginia Tech studying wood deck structural connectors.]

Cable & Other Guardrailing Systems - OSHA

Reader Question: are cable railings permitted by OSHA?

(Aug 5, 2015) Fran said:
Can these cables be applied for OSHA guardrailing?

This question was posted originally at CABLE RAILINGS & GUARDRAILS

Reply: OSHA requirements for fall protection for workers

There is not an explicit discussion of cable railings and guardrails in the OSHA language, as you'll see in the citation below. My OPINION is that because of the tension required to provide secure cable railings the time, cost and trouble of installing a cable system instead of a more rigid system may be inconvenient at some jobsites even if OSHA would approve the system.

Where workers on a construction site are exposed to vertical drops of 6 feet or more, OSHA requires that employers provide fall protection in one of three ways before work begins:

• Placing guardrails around the hazard area.
• Deploying safety nets.
• Providing personal fall arrest systems for each employee.

Many times the nature and location of the work will dictate the form that fall protection takes. If the employer chooses to use a guardrail system, he must comply with the following provisions:

• Top edge height of top rails, or equivalent guardrail system members, must be between 39 and 45 inches above the walking/working level, except when conditions warrant otherwise and all other criteria are met (e.g., when employees are using stilts, the top edge height of the top rail must be increased by an amount equal the height of the stilts).
• Midrails, screens, mesh, intermediate vertical members, or equivalent intermediate structures, must be installed between the top edge and the walking/working surface when there is no wall or other structure at least 21 inches high.
  • Midrails must be midway between the top edge of the guardrail system and the walking/working level.
  • Screens and mesh must extend from the top rail to the walking/working level, and along the entire opening between rail supports.
  • Intermediate members (such as balusters) between posts must be no more than 19 inches apart.
  • Other structural members (such as additional midrails or architectural panels) must be installed so as to leave no openings wider than 19 inches.
  • Guardrail systems must be capable of withstanding at least 200 pounds of force applied within 2 inches of the top edge, in any direction and at any point along the edge, and without causing the top edge of the guardrail to deflect downward to a height less than 39 inches above the walking/working level.
• Midrails, screens, mesh, and other intermediate members must be capable of withstanding at least 150 pounds of force applied in any direction at any point along the mid rail or other member.
• Guardrail systems must not have rough or jagged surfaces that would cause punctures, lacerations, or snagged clothing.
• Top rails and midrails must not cause a projection hazard by overhanging the terminal posts.

Source:

• OSHA, "Falls, Guardrail Systems", OSHA, U.S. Department of Labor, Occupational Safety & Health Administration, 200 Constitution Avenue, NW Washington, D.C. 20210 Tel: 1-800-321-OSHA (6742) , Website: https://www.osha.gov/html/Feed_Back.html - retrieved 24 Aug 2015 original source https://www.osha.gov/SLTC/etools/construction/falls/guardrail.html in turn citing:
  • 29 CFR 1926 Subpart M, Fall protection. OSHA Standard.
  • 1926.501, Duty to have fall protection
  • 1926.501(b)(1), Unprotected sides and edges
  • Worker Deaths by Falls: A Summary of Surveillance Findings and Investigative Case Reports. US Department of Health and Human Services (DHHS), National Institute for Occupational Safety and Health (NIOSH) Publication No. 2000-116, (2000, September).

Glass & Laminated Glass Railings, Guardrails: strength & testing codes & standards

• ASTM E2353 - 06 Standard Test Methods for Performance of Glass in Permanent Glass Railing Systems, Guards, and Balustrade
  Partial quote from the ASTM abstract:
  
  These test methods are intended to provide information from which applicable design data can be derived for the performance of glass in rails, guards and balustrade systems as infill panels that are fastened to concrete, masonry, wood and metal as well as related products, and to the performance of glass as the structural element of the rail, guard, or balustrade system.
  
  Specification E 329 and Practice E 699 are standards that assist the user of these test methods to apply appropriate procedures and methods to ensure a quality result is provided.
• "Use of Laminated Glass in Glass Railing Systems", Glass Informational Bulletin GANA LD 09-0311, March 2011, Glass Association of North America, 800 SW Jackson Street, Suite 1500 Topeka, KS 66612 (785) 271-0208 Fax: (785) 271-0166 www.glasswebsite.com, retrieved 02/04/2013 [LD 09-0311 - Use of Laminated Glass in Glass Railing Systems.pdf]

Our photograph above shows a glass panel guardrailing atop a balcony as well as a glass guard along the stairwell itself. I'm doubtful that the balcony glass guard meets the requirements of the IBC and note that there is no top railing along the glass guard enclosure.

There is a "handrailing" along the glass guard on the stairs themselves: I forgot to measure the handrailing height - it may be a bit high for some stair users.

Reader Question: are guardrailings required along the top of glass guardrails on balconies or decks?

I'm building a glass guardrailing around my deck overlooking a lake. Do I need a railing along the top of the glass or is the glass strong enough to meet code?

Reply:

At left we illustrate a glass guardrailing as well as a glass stair rail (at right in the photo) installed in a shopping mall in New York City.

Note the position of the stair-user's right hand (red arrow- click to enlarge any image) suggesting that while the railing along the top of the glass guards at both balcony and along the stair may serve to meet the code requirements below, the position of the rail along the top of the stair guard may be too high for comfortable use by people walking on the stairs. [For privacy we blurred the faces of the pedestrians in this photo - Ed.]

According to the ICC, a top rail, at a height of 42" above the walking surface is required along a glass guardrail will be required unless the glass panels themselves will meet the structural strength required by IBC 1607.7.

• IBC 2407.1.1 Loads. The panels and their support system shall be designed to withstand the loads specified in section 1607.7. A safety factor of 4 shall be used.
• IBC 1607.7, the load requirements are for a 50 pound per foot uniform load or a 200 pound concentrated load applied
  at any point along the top of the guard.

Considering the safety factor cited from the IBC for the top rail it is unlikely that glass panels will meet that requirement. (Wagner Companies ret. 2015).

The top rail should continue to meet the guardrailing load requirements even should a glass panel itself fail, fall, or break. Note that you may be required to use laminated, tempered or safety glass for glass guards in your area. Check with your local building official by providing the plan and design specifications for your glass guardrailing system as obtained from your professional engineer or architect.

Note that the above is only discussing the top rail along a glass guardrail or stair guard. In addition to a top rail, along a stair guard or ramp that is enclosed by glass "guards", a handrailing will be required at a height between 34" and 38".

In-Situ Testing of Guardrails & Handrails

• [Additional handrail test requirement citations wanted - Contact Us]
• Florida: "Checklist #0460 for the approval of: Railings (Stairs & Balcony)", Miami-Dade County, Florida Building and Neighborhood Compliance Department Product Control Section, Balustrade & Plastic Railing
  
  Perpendicular to railing load test, with loading per conditions specified in section 1618.4.6 of the Florida Building Code,
  
  On a minimum 8-ft section and 3 posts.
  
  Test load shall be 2 times the design load, with minimum 80% recovery.
  
  Internet mail address: bldgdept@miamidade.gov Homepage: http://www.miamidade.gov/building - Web search 02/04/2013, original source: http://www.miamidade.gov/building/library/checklists/railings.pdf, copy on file as FL_MIami_Railings.pdf
• Florida 2010 building code,
  • Section 504 STAIRWAYS
    
    "All steps on a flight of stairs shall have uniform riser heights and uniform tread depths. Risers shall be 4 inches (100 mm) high minimum and 7 inches (180 mm) high maximum. Treads shall be 11 inches (280 mm) deep minimum. Open risers are not permitted." etc.
  • SECTION 1714 IN-SITU LOAD TESTS . websearch 02/04/2013, original source: http://www2.iccsafe.org/states/florida_codes/ [handrails are not explicitly cited here]
• Section 1012 - Handrails, [begins p. 84] Florida Building Code Handbook, State Requirements for New Educational Facilities Construction, Florida Department of Education 2007, retrieved 02/04/2013, original source: http://www.fldoe.org/. This edition of the Florida Building Code handbook is a modification of the original 2004 Florida Building Code Handbook that was developed for the Department of Education
• GUARDRAIL POST CODES & SPECS

Metal Railings, Guardrails, Handrails testing standards

• ASTM E894 - 88(2010) Standard Test Method for Anchorage of Permanent Metal Railing Systems and Rails for Buildings
• ASTM E935 - 00(2006) Standard Test Methods for Performance of Permanent Metal Railing Systems and Rails for Buildings.
  Partial quote from the ASTM abstract:
  
  These test methods are intended to provide information from which applicable design data can be derived for the performance of metal railing systems and rails installed and fastened to structural elements of concrete, masonry, wood, and metal as well as related products.
  • 1.1 These test methods cover procedures to be followed in testing the performance of permanent metal railing systems (guard, stair, and ramp-rail systems) and rails (hand, wall, grab, and transfer rails) installed in and for agricultural, assembly, commercial, educational, industrial, institutional, recreational, and residential buildings.
  • 1.2 These test methods are applicable to such railing systems and rails having major structural components made of metal, with their secondary components made of metal or other materials such as wood, plastic, and glass.
  • 1.3 These test methods can be used to determine whether permanent metal railing systems and rails comply with anticipated performance requirements of the applicable specifications, codes, and standards, such as those described in Specification E 985.
  
  
• ASTM E985 - 00(2006) Standard Specification for Permanent Metal Railing Systems and Rails for Buildings
  Partial quote from the ASTM abstract:
  
  This specification covers permanent metal railing systems (such as guard, stair, and ramp-rail systems) and rails (such as hand, wall, grab, and transfer rails) for use in agricultural, assembly, commercial, educational, industrial, institutional, recreational, and residential buildings. Also covered in this specification are basic design requirements and considerations, and minimum criteria for load and deflections; however, it does not cover design criteria for specific field conditions.
  
  Railing systems and rails shall be manufactured with major structural components made of metal and secondary components made of metal, wood, plastics, or glass, and shall withstand forces that may potentially be exerted by building users. Tests for static loading and deflection shall be performed and shall conform to the requirements specified.
  • .1 This specification covers permanent metal railing systems (guard, stair, and ramp-rail systems) and rails (hand, wall, grab, and transfer rails) installed in and for agricultural, assembly, commercial, educational, industrial, institutional, recreational, and residential buildings.
  • 1.2 This specification is intended to be applied to permanent metal railing systems for buildings and to such railing systems and rails having major structural components made of metal, with their secondary components made of metal or other materials such as wood, plastics, and glass.
  • 1.3 This specification considers that today's and tomorrow's overall outlook is based on the health and safety of all potential users of buildings. The criteria incorporated in this specification provide for normal and anticipated building uses, but not for abuses for which the building and its components are not designed.
  • 1.4 This specification establishes basic minimum requirements and criteria that lead to satisfactory products under normal use conditions and does not give consideration to design criteria for specific field conditions, the establishment of which is the prerogative and responsibility of the designer, specification writer, and code agencies.
• ASTM F 2408 Standard Specification for Ornamental Fences Employing Galvanized Steel Tubular Pickets

Plastic Railings, Guardrails, Handrails testing standards

• ASTM F1092 - 04(2010) Standard Specification for Fiberglass (GRP) Pultruded Open-Weather Storm and Guard, Square Railing Systems
  Partial quote from the ASTM abstract:
  
  This specification provides the material requirements, construction, installation, and testing requirements for open-weather deck, storm-and-guard, fiberglass square railing systems.

  • 1.1 This specification provides the material requirements, construction, installation, and testing requirements for open-weather deck, storm-and-guard, fiberglass square railing systems. Components are to be manufactured by the pull-trusion process.

  • 1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

  • 1.3 The following safety hazards caveat pertains only to the test methods portion, Section 9, of this specification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Wood-Plastic Composite Railings, Guardrails, Handrails testing standards

• ASTM D7032 - 10a Standard Specification for Establishing Performance Ratings for Wood-Plastic Composite Deck Boards and Guardrail Systems (Guards or Handrails).
  Partial quote from the ASTM abstract:
  
  This specification presents the standard procedures for establishing the performance rating of wood-plastic composite (WPC) deck boards and guardrail systems (guards or handrails). The purpose of this specification is to establish the basis for code recognition of these products or systems in exterior applications where combustible construction is allowed. ...
  
  In the same manner, guards and handrails are additionally analyzed through concentrated load tests, and one- and two-family dwelling requirements.

• 1.1 This specification covers the procedures to establish a performance rating for wood-plastic composite (WPC) deck boards.
• 1.2 Deck boards, guards, and handrails covered by this specification are permitted to be of any code compliant shape and thickness (solid or non-solid).
  
  Note 10 ... requirements are based on the building code and a safety factor of 2.5.
  
  Concentrated test load for guards - A 500-psf [pounds per foot] load shall be applied … at critical locations … such as mid span of top rail, top rail alongside a post and at the top of a post.


• CCMC Technical Guide for PVC Guard Systems

Wood Railings, Guardrails, Handrails, testing & strength standards

• ANSI: “American Standard Safety Code for Floor and Wall Openings, Railings, and Toe Boards,” AS A12 -1932. New York: American Standards Association, approved May 3, 1932.
• ANSI “USA Standard Safety Requirements for Floor and Wall Openings, Railings, and Toe Boards,” USAS A12.1-1967. New York: American National Standard Institute, approved March 17, 1967.
• ANSI “American National Standard Safety Requirements for Floor and Wall Openings, Railings, and Toeboards,” ANSI A12.1-1973. New York: American National Standards Institute, approved March 15, 1973.
• BOCA “Special Loads,” Section 1615.0, The BOCA National Building Code/ 1993. Country Club Hills, IL: Building Officials & Code Administration International, Inc. 1993, pp. 185 – 186.
• USAS “Requirements for Fixed Industrial Stairs,” USAS A64.1-1968. New York: American National Standards Institute, approved February 16, 1968.
• OSHA “Fall Protection,” 29 CFR 1926.451(g)(4)(vii). Washington, D.C., Occupational Safety and Health Administration; Chapter XVII, 7/1/99 edition.
• ICC-ES AC174 Acceptance Criteria for Deck Board Span Ratings and Guardrail Systems (Guards and Handrails)
• ICC-ES AC273 Acceptance Criteria for Handrails and Guards
• Plans for Crash-Tested Wood Bridge Railings for Concrete Decks, U.S. Forest Products Laboratory, web search 02/04/2013, original source http://www.fpl.fs.fed.us /documnts/fplgtr/fplgtr108 /fplgtr108.pdf, copy on file as Wood_Rail_FPL_fplgtr108.pdf
  
  Also see NCHRP. 1981. Recommended procedures for the safety performance evaluation of highway appurtenances. NCHRP Rep. 230. Washington, DC: National Research Council, Transportation Research Board, National Cooperative Highway Research Program.

Railing & Handrail Strength & Failure Studies

• Ralph L. Barnett* and William G. Switalski, "Case Study The Safety of Wood Railings", Triodyne Inc. Consulting Engineers & Scientists – Safety Philosophy & Technology 5950 West Touhy Avenue Niles, IL 60714-4610 (847) 677-4730 FAX: (847) 647-2047 e-mail: infoserv@triodyne.com www.triodyne.com, web search 02/04/2013, original source: http://www.triodyne.com/SAFETY~1/Sb_v18n1.pdf, copy on file as BarnettSwitalski_Railing_Study.pdf.
  
  Abstract: When the handrail assembly broke away from a wooden deck attached to the rear of a private residence, the victim fell 12 feet to the lawn and sustained injuries rendering him a quadriplegic.
  
  Although the local building code required the handrail to withstand a 200 lb load applied in any direction at any point on the handrail, no guidance was given to the do-it-yourselfer who built the deck and railings to assure him that the final construction would produce an acceptable railing.
  
  The authors conducted testing and a statistical analysis of railing strength comparing the construction method used by the builder of the accident railing to another construction method utilizing a commercially available handrail bracket.
  
  The test program demonstrates that the strength of the wood used to build handrails can vary greatly and that a controlled method of building a handrail is necessary to ensure the integrity of a product intended to be consumer customized and assembled.
  
  It is necessary to have acceptable methods of railing construction because the failure of a railing joint can be life threatening. This is especially true in the consumer/do-it-yourself market where the designer/builder is not necessarily knowledgeable about building codes or construction methods.


• Joseph Loferski and Frank Woeste, P.E., "Strong Rail-Post Connections for Wooden Decks", The Journal of Light Construction (JLC), February 2005, web search 02/04/2013, original source http://www.dickseibert.com/Woeste.pdf, copy on file as Woeste_Rail_test.pdf

 

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Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2022-05-27 by Anonymous: regulations for balcony guardrailings considering dynamic loading force?

Do you have any specific regulation for building balcony handrail on dynamic loading force?

Because, dynamic loading force is normally bigger than statistic load as you well know,

Best regards,

- Anonymous by private email

On 2022-05-27 by InspectApedia-911 (mod)

@Anonymous

Thank you for the interesting question about the dynamic loading force on guardrails or handrails.

You'll see that the force requirements are expressed rather simply - at least in North America. For example while a force in pounds is specified, there's no consideration given to speed. I think that's because of an assumption of the most-common situations in which a person falls against a handrail or guardrail (or grasps the rail in an effort to arrest a fall) and the acceleration associated with that fall.

That is to say the acceleration and distance of movement between the person and the guard or handrail is rather small.

So in designing handrails and guardrails for human activity, it's the static load that gets primary consideration.

Let me know what you think.

Note: my comments above pertain to pedestrian or human interaction with handrails and guardrails.

A very different view is taken with respect to guard rails along roadways or highways where the combination of mass and speed of vehicles is very significant.

Research on the Role of Dynamic Force on Guardrail & Handrail Strength Requirements & Testing

• Escamilla, Alfonso Cobo, María de las Nieves González García, and Nuria Llauradó Pérez. STATIC LOAD BEHAVIOR AND ENERGY ABSORPTION OF SAFETY GUARDRAILS FOR CONSTRUCTION WORKSs [PDF] Revista de la Construcción. Journal of Construction 15, no. 2 (2016): 46-54.
  Abstract
  
  One of the requirements which must be met by the temporary edge protection systems (TEPS) is to stop a worker who walks, stumbles, falls and knocks against the system. The effect of the worker’s crash with the protection system is a dynamic type stress applied as an impact.
  
  The capacity of the system to withstand the impact depends on its ductility and its ability to absorb energy. The area enclosed by the load-displacement graph of a TEPS when the load is statically applied is an indicator of its ductility and its ability to absorb energy.
  
  In Europe, the EN 13374 standard specifies the requirements to be fulfilled by the TEPS. For systems placed in floor slabs with a slope smaller than 10° (class A systems), the standard indicates that the testing should be performed using static loads.
  
  In this work, TEPS manufactured from steel, wood, injected plastic, and composites have been tested with the static loads test system specified in the EN 13374 standard for assessing class A systems.
  
  Subsequently, the areas enclosed in the load-displacement diagram have been tested and have been compared with the estimated values of impact energy.
  Keywords: safety guardrails, energy absorption, static load, accident, construction.
  
  This paper can be hard to retrieve so we include a copy here
• Racic, Vitomir, Aleksandar Pavic, and J. M. W. Brownjohn. "Experimental identification and analytical modelling of human walking forces: Literature review." Journal of Sound and Vibration 326, no. 1-2 (2009): 1-49.
• Maksud-Ul-Alam, Mohammad, and A. F. M. S. Amin. "Pedestrian induced vibrations in footbridges: Reappraisal of code provisions." In IABSE-JSCE Joint Conference on Advances in Bridge Engineering-II. 2010.
• Pinto, Armando, and Luis Reis. "Barrier for buildings: analysis of mechanical resistance requirements." Procedia Structural Integrity 1 (2016): 281-288.
  Abstract
  
  Barriers (guardrails and balustrades) prevents people from falling, for example, from balcony, open windows and stairs. Barriers also retain, stop or guide person in buildings.
  
  To increase the transparency of these components, traditional materials such as bricks, wood and metal are being replaced by glass or an organic material, which has mechanical behavior different from traditional materials.
  
  Regulation usually specify some action to take into account in the design of barriers, but do not define the required resistance. There are no international standards (ISO or EN) to assess the fitness for use of barriers, only national standards, with different testing loading conditions and mechanical resistance requirements.
  
  In this paper is presented a comparison of requirements and experimental testing conditions specified in standards from Portugal, Spain, France, UK, USA and Brazil.
  
  The goal of this research is to find some equivalence between standards, regarding the mechanical resistance behavior of different materials (brittle/ductile materials) and set a worst case scenario as the basis for the guardrails mechanical resistance profile.
  
  Some relations between the service limits state (plasticity) of metal guardrails and maximum deflection are proposed.
• Reid, John D., Jason A. Hascall, Dean L. Sicking, and Ronald K. Faller. "Inertial effects during impact testing." Transportation research record 2120, no. 1 (2009): 39-46.
  Abstract:
  
  Shortcomings were identified in historic dynamic guardrail post testing methods that could overestimate the strength of guardrail posts by a factor of two. This inaccuracy resulted from the influence of inertia that was not previously accounted for during dynamic component testing.
  
  The effects of inertia were verified and quantified with several analysis methods including nonlinear finite element analysis, which was used to develop a computer simulation of the dynamic tests. Several alternative testing procedures that could significantly reduce the effects of inertia were identified and investigated.
  
  One of these testing alternatives–-use of a crushable impact head–-was shown with computer simulation to reduce the effects of inertia and maintain the benefits of strain rate effects.
  
  The use of such an impact head is recommended for all future dynamic post strength testing. The results of the study imply that changes should be made not only in the standard design procedures used for guardrail and other vehicular barriers, which are clearly influenced by inertial effects, but in all designs that are based on dynamic strength testing.
  
  Dynamic testing is very common in the field of transportation engineering and care should be taken to ensure that inertial effects are considered when performing such tests.
• Wu, Weijia, and Robert Thomson. "A study of the interaction between a guardrail post and soil during quasi-static and dynamic loading." International Journal of Impact Engineering 34, no. 5 (2007): 883-898.

On 2022-05-27 by Anonymous

Anonymous - posted by moderator from private email

Thank you for your quick reply .
I’ll appreciated your concern.
My further comment is as follows .
Plese read and evaluate my understanding on dynamic force corrosion against hand rail.
Regards - Anonymous, in Japan

Comment:

Normally , if we confide to something with some speed “V”, it should be considered to count dynamic moving energy .

And then, dynamic moving energy is estimated as MV²

Therefore, total among of force will be reach to several times of static force.

When person’s weight is 50 kg weight , the person rushed to handrail, the received hand rail load force will be 50kg x 20 times or over =1000kg…..1 ton….. this means extremely bigger force will be given by dynamic corrosion .

In short, dynamic load force will be very bigger than statistic force.

On 2022-05-27 by InspectApedia-911 (mod) - role of velocity or momentum on handrail & guardrail strength requirements, failures, falls

@Anonymous in Japan

You raise and argue for a very interesting point, makes sense to me, and is not addressed in model building codes.
Indeed some of the most horrible accidents I've investigated have involved handrail and guardrail failures (or the absence of them entirely).

I'm not sure, however that we have an accurate idea of the speed with which someone rushes to an handrail, nor that their entire bodyweight is applied when the grasp it at that moment.

Where most or all body weight is applied to the rail is when someone is trying to arrest a fall that has started.

Aside: General comment on falls & force: (I'm not a physicist)

Just two weeks ago, I fell myself, walking on a flat EPDM (*Rubber) roof. My subjective time sense was less than a second. I was walking and then in "zero" time, wham! I was on my back on the roof. The roof surface had a coating of algae and was wet. The static coefficient friction of wet algae is one of the lowest substances known. Had this been a stair I'd not have even had time to grasp the handrail.

Had I fallen against a guardrail it'd have been 175 lbs static force + the momentum that might be achieved across the space between myself or a hand or torso, and the railing.

On stairwells people are no more than stairwell width from the handrail.

On a large balcony or deck that distance could be much greater, but I think that it would be rare for someone to be running towards the guardrail and then crash smack into it.

It will be instructive to look at actual research data on the contribution of momentum to loads on both handrails and guardrails.

Aside: another handrail failure I witnessed last year was a complete loss of connection of the handrailing to the wall in a private home when a heavy-set occupant, sitting on the lower step, pulled on the handrail simply to help raise himself to a standing position. It appears to me that at least in the U.S. handrail brackets widely sold in building supply stores may be seriously deficient in strength.

The stair user broke the handrail bracket nearest his hand and the railing then came off of the wall. I'm led from that field observation to focus more immediate attention on hand and guardrail connections.

Shopping at a Home Depot store a few months ago in preparing to add a hand railing along a stairway, I looked at two grades of handrail bracket available - I bought the stronger of the two but note that the stronger units were hard to find and much more costly.

No normal carpenter or railing installer would give a thought to the possibility that the mounting system was as weak and dangerous as I found it to be.

• Kinoshita, Satomi. "Handrail position and shape that best facilitate sit-to-stand movement." Journal of back and musculoskeletal rehabilitation 25, no. 1 (2012): 33-45.

There has been some research on the contribution of momentum in stair-falls (and perhaps in guardrail failures) - perhaps you have more expertise on this and can cite additional sources.

Below I cite a few findings from searching for "role of momentum in guardrail strength requirements" - though most discussions appear not to focus exactly on your argument.

In particular see the Komisar PDF copy that I attach, and the momentum data on p. 11

• Debelle, Héloïse, Carla Harkness-Armstrong, Kathryn Hadwin, Constantinos N. Maganaris, and Thomas D. O'Brien. "Recovery from a forward falling slip: measurement of dynamic stability and strength requirements using a split-belt instrumented treadmill." Frontiers in sports and active living 2 (2020): 82.
• Komisar, Vicki, Konika Nirmalanathan, and Alison C. Novak. "Influence of handrail height and fall direction on center of mass control and the physical demands of reach-to-grasp balance recovery reactions." Gait & Posture 60 (2018): 209-216.
• Komisar, Vicki, Konika Nirmalanathan, and Alison C. Novak. INFLUENCE OF HANDRAIL HEIGHT AND FALLING DIRECTION ON CENTER-OF-MASS CONTROL AND THE PHYSICAL DEMANDS OF REACH-TO-GRASP BALANCE RECOVERY REACTIONS [PDF] -
  
  Abstract:
  The ability to maintain and recover center of mass (COM) and trunk control after a destabilization is critical for avoiding falls and fall-related injuries. Handrails can significantly enhance a person’s ability to recover from large destabilizations, by enabling the person to grasp and apply high forces to the rail to stabilize their COM.
  
  However, the influence of handrail height and falling direction on COM control and the demands of grasping are unknown. We investigated the effect of handrail height (34, 38, 42 inches) and fall direction (forward, backward) on COM and trunk control, and the corresponding physical demands of reach-to-grasp balance reactions.
  
  Thirteen young adults were destabilized with platform perturbations, and reached to grasp a nearby handrail to recover balance without stepping. COM kinematics and applied handrail forces were collected. COM control was evaluated in terms of: (1) COM range and peak displacement, velocity and momentum in all Cartesian axes; and (2) trunk angular displacement, velocity and momentum in the roll and pitch axes.
  
  The physical demands of grasping were estimated via resultant handrail impulse. Compared to forward-directed falling, backward-directed falling was generally associated with greater peak COM and trunk angular displacement, velocity and momentum, along with greater handrail impulse. Higher handrails generally resulted in reduced peak COM and trunk angular displacement, velocity and momentum, as well as reduced handrail impulse.
  
  These results suggest that higher handrails(within the range of heights tested) may provide a stability advantage within the range of handrail heights tested, with better COM control achieved with lower physical demands of grasping.
• Park, Sungwoo, and James M. Finley. "Manual stabilization reveals a transient role for balance control during locomotor adaptation." bioRxiv (2019): 647453.
  

On 2019-09-17 by Taylor - maximum distance newel posts should be when on a ramp?

Re-Posted by (mod)

Taylor said:

What is the maximum distance newel posts should be when on a ramp?
Is there a certain type of screw/bolt that needs to be used to anchor the newel posts to concrete when mounting them outside?
What is the best way to mount the handrail to the newel post since the metal on the handrailing is so thin?

On 2017-01-23 by Damon Bourque - At what angle is the applied load required to be pulled at when applying the 800 lb.

At what angle is the applied load required to be pulled at when applying the 800 lb. (200 x factor of 4) to the top rail of a glass rail system

Moderator reply:

Taylor

I am not aware of a specific newel post separation distance on ramps; in my OPINON that distance will vary substantially depending on the guardrailing construction materials, newel post materials, ramp materials, and fasteners used.

The guardrailing's supporting posts must be sufficient to secure the guardrail against wobbling or worse, detachment, or breakage, or failure in response to side-loading forces .

Similarly, the proper attachments between balusters and guardrail top and bottom and attachments for handrailing depend on the materials involved. There is no single "fastener" that is proper for all possible materials. For example wood and steel handrailing connectors may be quite different.

This Q&A were posted originally at RAMP RAILING CODES https://inspectapedia.com/Stairs/Access_Ramp_Railing_Codes.php

...

Continue reading at GUARDRAIL POST CODES & SPECS or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

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Suggested citation for this web page

GUARDRAIL & HANDRAIL STRENGTH at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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INDEX to RELATED ARTICLES: ARTICLE INDEX to STAIRS RAILINGS LANDINGS RAMPS

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