When to apply OHSA over IBC and ACSE 1

[walrus102882]

I currently work for the Facility Department of a company classified as General Industry by OHSA, prior to this I worked for a private engineering firm designing bridges. Now I'm dealing with OHSA regulations and I'm curious how other people apply them. For example, I have been asked to look at some stairs. The stairs are structurally sound but the pitch/rise and run is steeper then allowed by todays codes. The building was constructed in the 1960's and I have over a dozen of this same type of stairs. I would like to say they are "grandfathered in" but the safety department says OHSA regulations apply and must always be meet first before in other building codes. Has any one had any experience dealing with existing conditions and current OHSA codes?

Thanks for your input!

 

[SlideRuleEra]

Stairs with a 6" run and 7" rise never met, or even came close to meeting any building code in the USA. Not 25 years ago, not 100 years ago. Engineers and builders have been aware of the proper ergonomics for stairs for long, long time. For example, take a look at the 151 page book "The Practical Stair-Builder", by C. Edward Loth. It was published in 1869. For a 7" rise the author recommends a run of between 9 1/2" to 11 1/4", depending on the experience based "formula" used for calculations. See page 86 and 87, at this link:

https://books.google.com/books?id=s...SCh1CQQDN#v=onepage&q=stairs rise run&f=false

These 1869 recommendations sound surprisingly modern. There has been some interest in recommending 7-11 stairs (7" rise, 11" run). There are pros and cons, of course, but they do work well - I used them in my own home. Home builders don't like them - they take up too much floor space, compared to high rise, narrow run stairs in common use. 7-11 stairs are well suited for wooden outdoor use. Use 2 x 12s for stringers, the 11" run is a perfect fit for a pair of 5/4 x 6 deck boards (true width 5 1/2" inches). Put a 1/2" gap between the two boards and you have a nice 1/2" nosing.

Here is a 1994, Chicago Tribune article discussing 7-11 stairs:

http://articles.chicagotribune.com/1994-01-08/news/9401080027_1_nahb-public-access-stairs-treads

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[Jerehmy]

If they didn't meet the code requirements of the day that were accepted in his municipality, then he really has no choice but to change them.

I'm aware of how dangerous short treads are. My basement steps are 8" CMU block (7.625" rise to 7.625" run). And the head clearance is like 5ft at one point. They're annoying to say the least.