There’s a 2 hour shaft wall (which they’ve indicated) then they have a furred out wall directly adjacent to the shaft wall. It looks like theyre trying to achieve some kind of acoustic separation. Again - you need to talk to the architect to better understand their design intent. Open Communication with all team members goes a long way on any project. You’re all trying to get a building built.

IMO - phone call before RFI, then formalize in an RFI.

To add to that, whenever possible, have a proposed solution. Even if it's wrong, the architect has the chance to explain and everybody comes out the better for it.

If the stair is part of the accessible route then it will need to be rated all the way around. If the stair isn't and depending on the assembly type the rating will need to extend a certain distance on the exterior walls perpendicular to the intersection. There are a lot of unknows still so it's very difficult to tell anything.

I have had plenty of stairs located along the perimeter of a building facing a public way. The exterior walls of these stairs have not had to be rated. Anyway, as you said, lot's of uknowns.

I have as well. Depending on the type of stair, required assembly and if they're part of the accessible exit they need to be rated to some extent.

I’m pretty sure the issue is that the gyp needs to be installed prior to the furring wall in this approach, meaning that the furring wall would need to go in after the roof, which is not ideal sequencing. However, furring walls over rated walls aren’t exactly uncommon. So the reality is that the contractor should be sequencing their construction with this in mind. Pretty decent odds they will have similar issues at party walls.

If there is a need/desire to accelerate this, or if they get the roof on and want to work on this in parallel abut don’t have the building fully dried-in (which seems likely) they can also look into options for water resistant gyp products. I wouldn’t recommend that if you just outright don’t have a roof though.

Oh I see now.

client too frugal for glass-matt sheathing when it likely the easiest/simplest solution? The amount of $ I'd end up charging a client to run an alternative solution to a life-safety issue like this will eclipse the premium of the sheathing product.

go do it - if you're the super then aren't you responsible for the means and methods? Why are you asking us for our opinions when we don't have all the information? You've already asked the architect.

You have to realize that you're asking us to do your job for you.  

Seems like the simplest solutions would be the DensArmor or some temporary enclosures. Dip into the contingency fund if the Owner won't approve the change order. This is not a hill you, or the project, need to die on.

Exactly EA. In addition, if the the owner wants to dictate means and methods that go beyond construction as shown in the CD's then the owner should pay for it.

I don't see the owner as trying to dictate means and methods. I see an architect that didn't account for constructability and typical sequencing in their design, and a contractor trying to propose the wrong solution to the problem. I also see the contractor not having coordinated their trades properly and it looks like they're going to have to remove some framing.

I could be wrong though.

I get the constructability part but the sequencing is means and methods. I'm not even sure if there is an issue with constructability at this point. The OP has confirmed that the drawings he/she provided aren't what's being built so . . . .

Whether sequencing is means and methods is probably an exercise in semantics. Regardless, I think we'd both agree it's the contractors purview. I still don't think the owner is trying to dictate it ... they just don't want to pay more for a material they don't think they should (I'd argue they haven't been fully educated to the issues and potential solutions).

The design as detailed (from what limited information we've been given) looks like a constructability issue. The fact they aren't following the drawings is more evidence to this. The more we're learning about this the more it looks like a giant cluster rather than something as simple as the OP wants it to be.

No one seems particularly blameless in all of it. Architect detailed something that was potentially impossible to build, Contractor didn't coordinate for changes to the details or for proper materials nor sequence the work to be able to construct per the design intent, Owner doesn't want to pay for changes that are valid and they should be willing to make.

I agree EA.

EA – That is a pretty fair analysis of the situation with the limited information I provided except the part about trade coordination. The crux of this whole issue is that we need a roof on before we can A). Run the other subs through, besides plumbing and electrical. B). The owner didn’t want the added expense of glass-mat. C). The insulator would not insulate the 2x4 stair wall without a roof. This left me to build as I am. Lessons learned: 1. Have the architect explain the constructability of this design within the limitations above. 2. Have my office and the architect educate the owner on a more sensible approach.                                                                                                                                             Everyone on this forum has had an owner that to some extent dictates means and methods and or design changes so this is not a novel situation that I am in but unfortunately the decisions made in ivory towers affect us poor ole’ field hands the most. :(                                                                                                                     You guys want to hear another good one? The owner wants to turn over a floor at a time to occupants! And my office is on board with this because they see a revenue stream because of the inconvenience! This means all life safety is complete.                Ain't that a hoot!

"...except the part about trade coordination."

Oh, so you told the framers to hold off on framing the furring wall on the unit side until the drywallers had installed the 2 layers of gyp on the unit side of the 2-hour rated stairwell wall? No, they just did all the framing anyway and made it so no one could access that area to install the necessary gyp board?

You're right I must be mistaken about the trade coordination.

I apologize for thinking you were asking for free services. A lot of people come here for free professional services. A few even have been hired by someone else to provide them with paid services and are literally asking us to assist them.

No worries Chad, we all are holding on to this spinning rock with bloody fingernails traveling through space at 67,000 mph while hoping there is still ice cream in the freezer when we get home.

Good news though, arch thinks that my markup solution will work. The firm's principle is coming for a site visit tomorrow and after he finishes his cappuccino & biscotti dolci :) I will get his opinion.

Principle or principal

If the detail 221 is accurate, your proposed changes to S-3 won't work to get you a 2-hour rating. Hoping the architect realizes that before the inspection. I've drawn you a little detail to illustrate your issue. Good luck.

You're reaching BulgarBlogger. Try harder.

EA - 221 isn't quite accurate. The 2x4 wall does not ballon up but instead has joist bearing on it as in the photo. I have the inspector coming out also to brainstorm. BB - I make that mistake almost every time. Thats what I get for joking on Architects I guess. Thanks all for the input!

If the joists are bearing on the 2-hour rated wall, why didn't you just wait to build out the furring walls on the unit side until the building was dried in and the 2-hour rated wall was rocked?

There is plumbing and electric in this wall

You missed my point

In addition - the supporting structure of the rated walls needs to be rated as well. 

Per EA's comment - why rated the furring wall? Why install the furring wall now. Instead, rated the exterior wall only, provide fire blocking, then add the furring wall at a later time.

If you're going to troll, try harder.

Winner Winner Chicken Dinner! How did you Know? The drawings don't have enough details and cuts for me. But I will make the building look like the picture anyway!

Um, are we not looking at structural framing details, with the exception being the stair section?

I see no project specific architectural details.

It is the lack of an arch section at the floor interface necessitating the RFI on how to achieve the specified rating, no?

I'm not sure I've ever seen a structural detail refer to the structural drawings for more information before. Seen it plenty in architectural drawings though.

guys none of these are structural details

here's a structural

 one that is posted above with keynotes

see below

I think it's an interesting problem, reminds me of an ARE question. I've certainly enjoyed the responses here.