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Guardrail collapse led to injury (C) Daniel Friedman Guardrail & Handrail Strength Requirements & Testing

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.

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

Deer Net deck rail (C) Daniel Friedman

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 Series Contents

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

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:

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:

Source:

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

Glass guardrailing & glass stair guard (C) Daniel Friedman

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:

Glass guard railing in New York City (C) Daniel Friedman

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.

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

Metal Railings, Guardrails, Handrails testing standards

Guardrail collapse led to injury (C) Daniel Friedman

Plastic Railings, Guardrails, Handrails testing standards

Wood-Plastic Composite Railings, Guardrails, Handrails testing standards

Wood Railings, Guardrails, Handrails, testing & strength standards

Railing & Handrail Strength & Failure Studies

 




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Reader Comments, Questions & Answers About The Article Above

Below you will find questions and answers previously posted on this page at its page bottom reader comment box.

Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

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.

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

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)

@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

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 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?

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

On 2017-01-23 by Damon Bourque

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


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