Another landing question

[Sifu]

Tried to add a sketch but I don't know how so I'll try to describe. Codes requires a landing outside of an exterior door, then exceptions it with a two riser allowance. Got that just fine. Code requires a landing to be 36" in the direction of travel. Imagine a condition where the 1st tread is at the level of the floor, just outside the door, then drops the two risers to grade. The door does not swing over the steps. Compliant? The top tread is not a compliant landing since it is only the depth of a tread. Only have two risers. Seems like it may not meet the letter of the code with less than a 36" landing but that having a tread at floor level would certainly not be more of a hazard than not having a tread at that level which is what you would have if you followed the letter of the code exception. I have looked in the commentary, Q&A and interpretations but can't find this. Anybody have a thought? (assuming you can follow it)

 

[pwood]

not compliant.

 

[KZQuixote]

Tried to add a sketch but I don't know how so I'll try to describe. Codes requires a landing outside of an exterior door, then exceptions it with a two riser allowance. Got that just fine. Code requires a landing to be 36" in the direction of travel. Imagine a condition where the 1st tread is at the level of the floor, just outside the door, then drops the two risers to grade. The door does not swing over the steps. Compliant? The top tread is not a compliant landing since it is only the depth of a tread. Only have two risers. Seems like it may not meet the letter of the code with less than a 36" landing but that having a tread at floor level would certainly not be more of a hazard than not having a tread at that level which is what you would have if you followed the letter of the code exception. I have looked in the commentary, Q&A and interpretations but can't find this. Anybody have a thought? (assuming you can follow it)

I don't see a problem. The exception to Section R311.3.2 does not address the location of the top riser. The presence of a two riser stairway out side of the door trumps the requirement for a landing. I'm assuming that this door is not the required egress door.

Bill

 

[mtlogcabin]

I am going to assume you are using the 2009 IRC and this is NOT the required exit door

R311.3.2 Floor elevations for other exterior doors.

Doors other than the required egress door shall be provided with landings or floors not more than 73/4 inches (196 mm) below the top of the threshold.

Exception: A landing is not required where a stairway of two or fewer risers is located on the exterior side of the door, provided the door does not swing over the stairway

I believe it is compliant under the IRC

 

[steveray]

Sounds compliant....as long as there are only two risers...it can be a tread at floor level....

 

[fatboy]

I believe it to be compliant under the IRC, two rises, is two rises. Doesn't matter if you start with the tread, or start with the rise.

 

[ICE]

I wonder where the requirement for two or fewer risers came from. Is there science behind it or is it a best guess?

 

[steveray]

ICE...I think it is the height and distance that most people will still be able to reach and negotiate the door and hardware without being on the steps at the same time....Or at least that is what I tell people....I might be wrong, but it sounds way better than "Because that's the code!"

 

[Mac]

Is ICE's picture showing three risers?

 

[Sifu]

I view the two riser rule as limiting the hazard from the inside, not the outside. I assume the codes are largely written to get people safely out of the house. With that in mind I see the limit of two risers as a limit on the distance someone may need to negotiate in an emergency exit scenario, in other words how far of a vertical drop and how far of a horizontal distance before hitting the ground if they leap out over dead space. At least thats the way I splain it when people start complaining. Right now I am having trouble seeing the location of the top tread at floor level as more hazardous than -73/4" but I look for other expert opinions to show me what I havn't thought of.

 

[steveray]

Is ICE's picture showing three risers?

I believe it is.....and the heights look off...

 

[Francis Vineyard]

I wonder where the requirement for two or fewer risers came from. Is there science behind it or is it a best guess?

Interesting that risers are a measurement between stair treads and we apply this to the door threashold presumably to the corresponding measurement for landings at doors.

It's not just the height to reach the door knob; a set of stair with a rise of 12 inches; 4 inch risers, 20 inch treads and no landing in front of the door is a very hazardous experience.

Francis

 

[ICE]

There is no maximum tread dept nor minimum riser height.

 

[steveray]

There is in CT......(Amd) R311.5.3.1 Riser height. The maximum riser height shall be 8 ¼ inches. The minimum riser height shall be 4 inches. Riser height shall be measured vertically between leading edges of adjacent treads.

And I would debate (as we already have) that the max tread is when it becomes a landing.....

And Good Point Francis......