Return to index: [Subject] [Thread] [Date] [Author]

RE: What about iron balusters and guardrails?

[Subject Prev][Subject Next][Thread Prev][Thread Next]
In general I agree with Mark's description of guardrails and handrails,
except that I think that the top rail of guardrails should generally act
similar to handrails, based on OSHA (as it applies to "all permanent places
of employment"). Below I have added some comments related to these
requirements:

OSHA also refers to "guardrail" as "railing" to act as a vertical barrier
and states "The top member of railing usually serves as a handrail". A
"standard railing" is generally required to prevent hazards due to falling
and may also be used at open sides of stairs. For a standard railing "The
top rail shall be smooth-surfaced throughout the length of the railing." (I
would apply this adjacent to various types of walking surfaces, even if not
a stair.) The structural design of railings of all types requires design for
a 200 lb load applied in any direction at any point on the top rail. OSHA
railings only require a top rail and an intermediate rail (i.e. for railings
at equipment platforms, tanks, etc). 

One difficult question is "When is an OSHA railing required and when is a
building code approved guardrail required?" Some locations are obvious but
there are many locations which are not so obvious, such as: inside an
equipment building which is not normally occupied; equipment floors within
an occupied building but at a lower level which is not regularly accessed;
exterior walkways, which are not directly part of an egress; etc. 

> -----Original Message-----
> From: Swingle, Mark [mailto:Mark.Swingle(--nospam--at)dcp.state.ma.us]
> Sent: Monday, July 31, 2000 2:49 PM
> To: 'seaint(--nospam--at)seaint.org'
> Cc: 'mswingle(--nospam--at)earthlink.net'
> Subject: Re: What about iron balusters and guardrails?
> 
> 
> Re: Guardrails and Handrails
> 
> This is a topic that is not too complicated, but is seldom 
> well-understood
> by structural engineers (at their peril).
> 
> Guardrails and handrails are two different items, which have 
> two different
> sets of structural design requirements.  Different codes vary 
> somewhat in
> the specific forces, but the concepts are all similar.
> 
> GUARDRAILS are required where there is a sudden change in 
> elevation greater
> than 30" (typical value).  Examples are balconies, decks, 
> retaining walls
> (if there is a walkway along the top), mezzanines, and the 
> open sides of
> stairs.  (The three exceptions I know of are the audience 
> side of a stage,
> trap doors in stages, and loading docks.  Try to imagine these with a
> guardrail....)
> 
> There are two distinct components of the guardrail: the top 
> rail, and the
> portion between the floor and the top rail, where the 
> balusters go (or maybe
> it is solid).  The top rail of the guardrail is not the same 
> as a handrail,
> except in special circumstances (see below).  The "top rail" 
> may not even be
> a rail in the true sense.  Picture a solid glass guard with 
> an integral rail
> at the top.
> 
> There are architectural requirements with respect to the 
> minimum height of
> the top rail of the guardrail and the maximum size sphere that can fit
> through the spaces in the baluster system (typical is 42" 
> high for top rail
> (36" for some residential) and a max 4" sphere through the 
> spaces).  There
> are NO requirements for grippability of the "top rail", 
> unless it is ALSO a
> handrail (see below).
> 
> There are structural design requirements for the capacity of 
> the top rail
> and the baluster portion to resist applied loads.  Typical is 
> a concentrated
> load applied in any direction to the top of the guardrail, OR 
> a uniform
> (line) load horizontally to the top of the guardrail, and a 
> uniform (areal)
> load on the entire baluster section.  Typical for UBC is EACH of the
> following, considered INDEPENDENTLY: 20 plf (residential) or 
> 50 plf (all
> others) on the top of the guardrail;  200 lbs in any 
> direction on the top
> rail; and 25 psf on the balusters.
> 
> HANDRAILS are required on stairs and ramps for gripping with the hand.
> 
> There are architectural requirements with respect to location 
> and size of
> handrails:  whether one or both sides of stairway (or ramp);  
> height above
> ramp or nosing of stair treads, distance from wall, min and 
> max sizes of
> grip, and extensions beyond the end of stair or ramp.  
> Typical are between
> 34" and 38" above nosing (to center), 1.5" min space, 1.25" 
> min and 2" (?)
> max diameter, 12" extensions (except residential stairs).  
> Residential only
> requires handrail one side (?), commercial two sides plus intermediate
> handrails where stairs are wider than 88" (?) etc.
> 
> There are structural design requirements for the capacity of 
> the handrail to
> resist applied loads.  Typical is a simultaneous horiz and 
> vert concentrated
> load at any point along the rail, 50 lbs each per Scott (?).
> 
> In some cases, the top rail of the guardrail and the handrail 
> are the same
> thing.  This occurs on some residential stairs where the architectural
> requirements allow the guardrail height to be the same as the handrail
> height.
> 
> My 2 cents.  I invite corrections, arguments, and criticism.
> 
> Mark Swingle
> 
> ------------------
> 
> On 29 July 00 Francisco Duarte wrote:
> 
> <do we need to design the iron balusters and railing systems? 
> If so where do
> we get info in terms allowable values.
> Are there any text books that have pretty much standard 
> construction details
> for different kinds of railing and guardrail systems.
> 
> <Same thing goes for stairs. 
> any comments will be appreciated
> 
> <Mil Gracias,
> <(thank you)
> 
> <F.D. (E.I.T)
> 
> ******* ****** ******* ******** ******* ******* ******* *** 
> *   Read list FAQ at: http://www.seaint.org/list_FAQ.asp 
> *   This email was sent to you via Structural Engineers 
> *   Association of Southern California (SEAOSC) server. To 
> *   subscribe (no fee) to the list, send email to 
> *   admin(--nospam--at)seaint.org and in the body of the message type 
> *   "join seaint" (no quotes). To Unsubscribe, send email 
> *   to admin(--nospam--at)seaint.org and in the body of the message 
> *   type "leave seaint" (no quotes). For questions, send 
> *   email to seaint-ad(--nospam--at)seaint.org. Remember, any email you 
> *   send to the list is public domain and may be re-posted 
> *   without your permission. Make sure you visit our web 
> *   site at: http://www.seaint.org 
> ******* ****** ****** ****** ******* ****** ****** ********
> 

******* ****** ******* ******** ******* ******* ******* *** 
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp 
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) to the list, send email to 
*   admin(--nospam--at)seaint.org and in the body of the message type 
*   "join seaint" (no quotes). To Unsubscribe, send email 
*   to admin(--nospam--at)seaint.org and in the body of the message 
*   type "leave seaint" (no quotes). For questions, send 
*   email to seaint-ad(--nospam--at)seaint.org. Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: http://www.seaint.org 
******* ****** ****** ****** ******* ****** ****** ********