Stair Landing Question

[Tom Jordan]

Hi all,

I'm working on a new house (Intern Architect for a Boston firm), and had a quick question about landing dimensions @ a stair to the basement. I've gone through the code, but can't find a direct answer to whether this stair works or not (specifically the jog in the landing/its dimensions). Please let me know your thoughts (images attached)

.

Thanks,

Tom

 

[TheCommish]

other than one or 2 family section 3, 2015 IRC with Ma. amendments, Section 10 of the 2015 IBC for commercial. Requirements for basement stairs are not any different then other staris

 

[SCBO1]

IMO if you make the 3'0" distance 4'4" it would meet the tread width requirement and wouldn't matter that you have a 5'0" landing depth. Don't know about MA code addendum's if any for stairs..

Why aren't you still recovering from the Pat's win? I know, your so use to them winning it's not fun anymore.
Like the Yankee's of old!

 

[cda]

Hi all,

I'm working on a new house (Intern Architect for a Boston firm), and had a quick question about landing dimensions @ a stair to the basement. I've gone through the code, but can't find a direct answer to whether this stair works or not (specifically the jog in the landing/its dimensions). Please let me know your thoughts (images attached)

.

Thanks,

Tom

Welcome, hope to visit Boston this fall

You have to be a sawhorse forum supporting person to direct post pictures


If you can make it a link

You can post the link

 

[Tom Jordan]

Thanks guys. I was hoping the 4'-7" dimension would somehow satisfy the requirement. The code describes other methods concerning the walkline. Is that not applicable in a switchback stair with no winders? I'm trying to match (or close to) a stacked switchback to the second floor, but as you can see, the foundation creates the jog. Ideally I would like to minimize the landing width. Looks like I'll have to get a bit more creative.

Oh I'm still recovering...I will be for the next few days

 

[Tom Jordan]

Welcome, hope to visit Boston this fall

You have to be a sawhorse forum supporting person to direct post pictures


If you can make it a link

You can post the link

Oh gotcha, thanks for letting me know! It seems to work if you right click and hit 'open image'.

 

[cda]

Oh gotcha, thanks for letting me know! It seems to work if you right click and hit 'open image'.

Sorry iphoneing

My right click don’t work

 

[Tom Jordan]

Sorry iphoneing

My right click don’t work

No worries, probably just another feature iPhone decided to skimp out on

Maybe I'll see ya in Boston this fall. Check out some of the brewery's if you get the chance!

 

[cda]

No worries, probably just another feature iPhone decided to skimp out on

Maybe I'll see ya in Boston this fall. Check out some of the brewery's if you get the chance!

That and wahlburgers

 

[MtnArch]

I only have access to the California Res Code and the online 2015 IRC, but it appears that R311.7.6 would allow this layout, since a 4'-4"R quarter circle would clear the corner of the protrusion.

 

[Tom Jordan]

I only have access to the California Res Code and the online 2015 IRC, but it appears that R311.7.6 would allow this layout, since a 4'-4"R quarter circle would clear the corner of the protrusion.

Thanks for your thoughts Alan, that is the impression I got as well...but every example I could locate showed this being applied to winders (no winders in this stair, just an odd shaped landing). I tend (hope) to agree that this would be applicable here as well...which would be great (and would allow me to reduce the landing a bit more). I'll run with this and plan for adjustments if required.

Thanks again.

 

[MtnArch]

The NFPA 101 Life Safety Code Handbook has a lot of examples and commentary explaining the "whys" and "wherefores". My 2009 version shows a great illustration (Exhibit 7.18) of the required widths and clearances for a commercial stair enclosure.

 

[Tom Jordan]

The NFPA 101 Life Safety Code Handbook has a lot of examples and commentary explaining the "whys" and "wherefores". My 2009 version shows a great illustration (Exhibit 7.18) of the required widths and clearances for a commercial stair enclosure.

Okay great, I'll take a look at those examples! The part of R311.7.6 (Landings for stairways) that I'm still a little unclear on is where the 'quarter circle' is measured from:

"Landings of shapes other than square or rectangular shall be permitted provided the depth at the walk line and the total area is not less than that of a quarter circle with a radius equal to the required landing width (4'4" in my case). Where the stairway has a straight run, the minimum depth in the direction of travel shall be not less than 36 inches (914 mm) (Good here)."

Does this sound like the quarter circle is measured from the walk line (12" off interior wall)? Or from the interior corner where the stair and landing meet?

Thanks again,

Tom

 

[MtnArch]

The illustration in the LSC shows the center at the corner/edge of the interior limits of the stair run and the radius extending to the outside limits of the stair run, but someone more knowledgeable than me will need to answer that.

 

[Francis Vineyard]

Wouldn't this measurement be for landings that "shall be no less than the width" of the stairs; otherwise how would you measure a flight without walls?