Stairway Lighting

[mjf]

Required width?

Required width?

I found this for stairwells:

IBC 1009.11.7 Stairway projections. Projections into the required width at each handrail shall not exceed 4.5 inches (114 mm) at or below the handrail height. Projections into the required width shall not be limited above the minimum headroom height required in Section 1009.2.

Would need to know what the required width of the stairwell is. Sounds to me like if stairwell is wider than what is required than an item could project further than 4.5 inches as long as it didn't exceed 4.5 inches into the required width.

If a stairwell is required to be 36"wide, but is built 40" wide.....could an item than protrude 8.5" without exceeding 4.5" into the required width?

 

[weressl]

Good point. I do not know. This is what is enforced around here and I always thought it included stairways.

So it seems like that lights built into the bottom of the handrails or installed on the wall ABOVE the required headroom would meet the compliance.

(Yeah, I been preaching this - the replacement practicability - for 20+ years now, except I don't get involved in too many building structures, just open steelwork stairways. Diff'rent kettle of fish...

 

[jumper]

So it seems like that lights built into the bottom of the handrails or installed on the wall ABOVE the required headroom would meet the compliance.

I believe so.

 

[jumper]

If a stairwell is required to be 36"wide, but is built 40" wide.....could an item than protrude 8.5" without exceeding 4.5" into the required width?

I do not have a clue. Where are all the inspectors on this forum? Raider or someone, pick up the phone!

 

[dbuckley]

... 3 mercury vapour lamps, all in parrelal, from the same ballast. Re-lamping would only be required when all 3 lamps had burnt out, which could take 10 years or more. It is also possible to wire several metal halide lamps from one ballast...

Now these are tricks I've not heard of before - neat idea!

 

[iwire]

One building I worked in had lights at the top of stairwells that required costly and disruptive scaffolding to reach.
I solved, or at least postponned, the problem by installing fixtures that used 3 mercury vapour lamps, all in parrelal, from the same ballast.
Re-lamping would only be required when all 3 lamps had burnt out, which could take 10 years or more.

It is also possible to wire several metal halide lamps from one ballast, again re-lamping wont be needed until all have failed, which could take many years.

In the case of linear flourescent lamps that have only a single pin at each end, any number may be wired to one ballast, only one will light.

Can you explain more?

 

[ptrip]

You stated an ADA Law. I would guess stairways would not be affected much by the ADA law. Just a guess.

ADA is more than wheelchairs. The blind use stairwells ... and they're the ones the protrusions affect most. The point of not having fixtures (or anything else for that matter) protruding into a corridor or stairwell at the listed heights is so as they walk along the wall (using their hands or sticks or whatever to maneuver) they don't smack their heads into those objects.

I've been pondering the stairwell lighting issue recently. I remember there being a product out there that was a linear fixture with two lamps, one on an integral occ sensor and one that was on 24/7 for emergency purposes. Any hints as to who carries that? I can't remember.

In addition to above ... I'd like to find something that is more "aesthetically pleasing" for the Architect's (and Owner's) sake. Everything I see that might fit the bill is an ugle square end cheapo looking stock flourescent fixture (thought it still needs to be inexpensive). I know ... I'm asking for the world! :roll:

 

[RICK NAPIER]

So far we have only discussed the IBC this is from the IRC

R311.7 Stairways.
R311.7.1 Width. Stairways shall not be less than 36 inches (914 mm) in clear width at all points above the permitted handrail height and below the required headroom height. Handrails shall not project more than 4.5 inches (114 mm) on either side of the stairway and the minimum clear width of the stairway at and below the handrail height, including treads and landings, shall not be less than 311/2 inches (787 mm) where a handrail is installed on one side and 27 inches (698 mm) where handrails are provided on both sides.

Exception: The width of spiral stairways shall be in accordance with Section R311.7.9.1.
R311.7.2 Headroom. The minimum headroom in all parts of the stairway shall not be less than 6 feet 8 inches (2032 mm) measured vertically from the sloped line adjoining the tread nosing or from the floor surface of the landing or platform on that portion of the stairway.

Exception: Where the nosings of treads at the side of a flight extend under the edge of a floor opening through which the stair passes, the floor opening shall be allowed to project horizontally into the required headroom a maximum of 43/4 inches (121 mm).R311.7 Stairways.

R311.7.1 Width. Stairways shall not be less than 36 inches (914 mm) in clear width at all points above the permitted handrail height and below the required headroom height. Handrails shall not project more than 4.5 inches (114 mm) on either side of the stairway and the minimum clear width of the stairway at and below the handrail height, including treads and landings, shall not be less than 311/2 inches (787 mm) where a handrail is installed on one side and 27 inches (698 mm) where handrails are provided on both sides.

Exception: The width of spiral stairways shall be in accordance with Section R311.7.9.1.R311.7.2 Headroom. The minimum headroom in all parts of the stairway shall not be less than 6 feet 8 inches (2032 mm) measured vertically from the sloped line adjoining the tread nosing or from the floor surface of the landing or platform on that portion of the stairway.

Exception: Where the nosings of treads at the side of a flight extend under the edge of a floor opening through which the stair passes, the floor opening shall be allowed to project horizontally into the required headroom a maximum of 43/4 inches (121 mm).With no article for protruding objects.

 

[dbuckley]

Can you explain more?

I wrote above that this was a neat trick, 'cos I hadn't heard it before. But now its been pointed out to me, its a case of Doh! Why didn't I think of that...

There are several paralleled lamp and one ballast. Mercury vapour lamps have a striking voltage, the voltage at which the lamp starts to conduct electricity. The voltage varies a bit lamp to lamp due to manufacturing spreads and such like.

As the voltage applied across the lamp through the ballast on the half wave rises, one of the paralleled lamps will strike - the one with the lowest striking voltage. The striking and running voltage of a mercury vapour lamp are different. The ballast limits the current flow. Once the first lamp strikes and conducts, the voltage across all the lamps drops, so the lamp(s) with higher striking voltages never get a chance to start. So just one lamp of the collection starts up.

When the lamp with the lowest striking voltage fails, then the lamp with the next lowest striking voltage steps up to the plate.

I'm more surpised it works on discharge lamps with ignitors, but am very willing to bow to experience!

 

[mivey]

I wrote above that this was a neat trick, 'cos I hadn't heard it before. But now its been pointed out to me, its a case of Doh! Why didn't I think of that...

There are several paralleled lamp and one ballast. Mercury vapour lamps have a striking voltage, the voltage at which the lamp starts to conduct electricity. The voltage varies a bit lamp to lamp due to manufacturing spreads and such like.

As the voltage applied across the lamp through the ballast on the half wave rises, one of the paralleled lamps will strike - the one with the lowest striking voltage. The striking and running voltage of a mercury vapour lamp are different. The ballast limits the current flow. Once the first lamp strikes and conducts, the voltage across all the lamps drops, so the lamp(s) with higher striking voltages never get a chance to start. So just one lamp of the collection starts up.

When the lamp with the lowest striking voltage fails, then the lamp with the next lowest striking voltage steps up to the plate.

I'm more surpised it works on discharge lamps with ignitors, but am very willing to bow to experience!

That is neat.

 

[ericgold]

Found some information on paralleled lights here: http://members.misty.com/don/f-lamp.html#wd9a

 

[broadgage]

As posted on page 2 of this thread, mercury vapour lamps will work fine several in parralell on one ballast.
The fixture will remain lit until all lamps have failed, which could take many years.

High pressure sodium or metal halide lamps can also be used, but I suspect that only lamps that have an external ignitor built into the fixture would work.
I do not believe that lamps with a built in ignitor would be suitable.
The draw back of this approach is that failure of the ignitor would disable all lamps. (the ignitor should have a long life though, they are normaly killed by repeated efforts to strike a failed lamp. This wont happen with multiple lamps until they all fail)
Mercury lamps are better in this respect as most small ones start from line voltage and dont need an ignitor.

Some types of flourescent ballast use only two wires from ballast to lamp, these ballasts may be connected to almost any number of lamps.
Only the lamp with the lowest sriking voltage will light, and the fixture will remain lit until all lamps have failed, which could take many, many years.

Ballasts with four wires to the lamp can sometimes be connected to two lamps, but not all types are suitable.

CFLs with an internal starter and external ballast can also be wired several lamps to one ballast, and again only one lamp will light.
This is however less satisfactory due to the internal starters.

 

[iwire]

Well I have learned something new here but I doubt I can use it due to listing requirements and NEC 110.3(B).

 

[Ragin Cajun]

I generally spec wall mounted fluorescent fixtures with up/down light. Inexpensive, easy to install and relamp.

Where you need long life in a difficult location, use induction lighting with the ballast in a convenient location. Many manufactures now carry them.

RC

 

[B4T]

I looked a one today.. 8 X 8 square recessed light in a stairway that you need a 16' stepladder to reach.

I talked them into taking out the light, putting a medallion to cover the drywall patch, and putting a hanging 10" white ball on 8' of chain

I can put a pancake box on top of the drywall and we are done. :grin:

 

[ptrip]

I generally spec wall mounted fluorescent fixtures with up/down light. Inexpensive, easy to install and relamp.

Where you need long life in a difficult location, use induction lighting with the ballast in a convenient location. Many manufactures now carry them.

RC

Mfr/Model? I've been looking for this recently and am having trouble finding an "aesthetically pleasing" one!

Thanks!

 

[Ragin Cajun]

"aesthetically pleasing" ???

Lithonia , etc. all have wall mounted fixtures with up/down light. They are generally about as plain as can be. Typically my projects are apartment complexes, "simple" office buildings, etc. that don't require "aesthetically pleasing" lights in the stairways.

If you have a fancy stairway, that's going to require help from your lighting rep. A good lighting rep is a good person to get to know.

RC

 

[ptrip]

"aesthetically pleasing" ???

Lithonia , etc. all have wall mounted fixtures with up/down light. They are generally about as plain as can be. Typically my projects are apartment complexes, "simple" office buildings, etc. that don't require "aesthetically pleasing" lights in the stairways.

If you have a fancy stairway, that's going to require help from your lighting rep. A good lighting rep is a good person to get to know.

RC

I'm pretty much all schools right now. Basic is "fine" ... but I like to dress things up a bit if possible (and not terribly expensive). I don't know what I'm looking for ... so it makes it difficult on my reps.

Because of lighting output, ADA restrictions and cost ... I'm probably left with the standard corridor units (which is what is currently spec'd). Ah well.

Thanks anyway!

 

[hurk27]

Found some information on paralleled lights here: http://members.misty.com/don/f-lamp.html#wd9a

Got to love the Samuel M. Goldwasser humor LOL

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