1hr party wall assembly with no airgap and staggered studs?

[steveray]

Let's "repair" the plumbing with lead solder too!

They're building a new wall, it needs to meet the current building code, it's not even gray.

Show me yours ill show you mine...

P2906.2.1​

Pipe, pipe fittings, joints, valves, faucets and fixture fittings utilized to supply water for drinking or cooking purposes shall comply with NSF 372 and shall have a weighted average lead content of 0.25-percent lead or less.

This does not look like a new plate, so I ASSUME not a new wall..And it looks very gray to me...maybe white.....:

 

[redeyedfly]

Show me yours ill show you mine...

P2906.2.1​

Pipe, pipe fittings, joints, valves, faucets and fixture fittings utilized to supply water for drinking or cooking purposes shall comply with NSF 372 and shall have a weighted average lead content of 0.25-percent lead or less.

This does not look like a new plate, so I ASSUME not a new wall..And it looks very gray to me...maybe white.....:

View attachment 14716

All the parts that make it sound compliant will be new work. QED

 

[mtlogcabin]

This is why I asked if this project falls under the 50% criterion. That determines whether it can be repaired with in-kind construction or if the replaced construction has to meet the current code.

50% criterion is not included in Chapter 4 repairs.

301.1 General.
The repair, alteration, change of occupancy, addition or relocation of all existing buildings shall comply with Section 301.2, 301.3, or 301.4.

301.2 Repairs.
Repairs shall comply with the requirements of Chapter 4.

302.3 Additional codes.
Alterations, repairs, additions and changes of occupancy to, or relocation of, existing buildings and structures shall comply with the provisions for alterations, repairs, additions and changes of occupancy or relocation, respectively, in this code and the International Energy Conservation Code, International Fire Code, International Fuel Gas Code, International Mechanical Code, International Plumbing Code, International Private Sewage Disposal Code, International Property Maintenance Code, International Residential Code and NFPA 70. Where provisions of the other codes conflict with provisions of this code, the provisions of this code shall take precedence.

The IBC is not referenced

The OP asked for help in finding a code compliant staggered stud fire assembly and that has been provided.

 

[steveray]

All the parts that make it sound compliant will be new work. QED

Except there is nothing that requires it so it won’t be new work….

 

[redeyedfly]

LOL, OK. Buildings gutted by fire get grandfathered in to code from original construction when rebuilt.

It's almost like you guys want to pick the most unreasonable approach and argue it.

OP, you will be able to hear the neighbor tenants whisper to each other if you slap a single layer of gyp on each side of that "repaired" wall.

 

[Yikes]

LOL, OK. Buildings gutted by fire get grandfathered in to code from original construction when rebuilt.

It's almost like you guys want to pick the most unreasonable approach and argue it.

OP, you will be able to hear the neighbor tenants whisper to each other if you slap a single layer of gyp on each side of that "repaired" wall.

Nope, if we follow Texas IEBC, only a building in a burned condition where repair costs 49.99999999% or less of the pre-damage market value gets to be restored back under the requirements of the code that was applicable at time of original construction. That's what the IEBC considers to be a "reasonable" approach to repairs. In that scenario, the neighbors will hear each other no more or no less than they did pre-fire damage. If the owner wants it quieter than that, then it becomes an upgrade/alteration, not a "repair".
From post #12:

 

[steveray]

LOL, OK. Buildings gutted by fire get grandfathered in to code from original construction when rebuilt.

It's almost like you guys want to pick the most unreasonable approach and argue it.

OP, you will be able to hear the neighbor tenants whisper to each other if you slap a single layer of gyp on each side of that "repaired" wall.

Correct…it’s a minimum code…they always have the chance to do better…

 

[steveray]

Nope, if we follow Texas IEBC, only a building in a burned condition where repair costs 49.99999999% or less of the pre-damage market value gets to be restored back under the requirements of the code that was applicable at time of original construction. That's what the IEBC considers to be a "reasonable" approach to repairs. In that scenario, the neighbors will hear each other no more or no less than they did pre-fire damage. If the owner wants it quieter than that, then it becomes an upgrade/alteration, not a "repair".
From post #12:

View attachment 14717

And 405 only applies to structure

 

[Paul Sweet]

"Correct…it’s a minimum code…they always have the chance to do better…"
But will the insurance company pay for the "upgrade"?

 

[steveray]

"Correct…it’s a minimum code…they always have the chance to do better…"
But will the insurance company pay for the "upgrade"?

Exactly...I am not perfect, but I can't cost someone money by making them do what is not required and I can't let them do any less than what is required.....So I guess I need to be perfect....

 

[Yankee Chronicler]

50% criterion is not included in Chapter 4 repairs.

See post #12 and post #30. I explained how it applies. The key is whether or not the repair is for "substantial" structural damage.

 

[Yankee Chronicler]

Exactly...I am not perfect, but I can't cost someone money by making them do what is not required and I can't let them do any less than what is required.....So I guess I need to be perfect....

As Chris Laux (former State Building Inspector) used to say, "The code is the most you can require and the least you can accept."

That initially sounds like an impossible tightrope to walk ... until you realize that from an enforcement perspective we should never prevent someone from exceeding the code. We can't require that they exceed the code ... but we shouldn't oppose doing so.

 

[mtlogcabin]

Substantial Damage or Substantial Improvement definitions would not be applicable since this is a fire damage repair and not flood damage repairs.

2018 IEBC
[BS] SUBSTANTIAL STRUCTURAL DAMAGE. A condition where any of the following apply:

1. The vertical elements of the lateral force-resisting system have suffered damage such that the lateral loadcarrying capacity of any story in any horizontal direction has been reduced by more than 33 percent from its predamage condition.

2. The capacity of any vertical component carrying gravity load, or any group of such components, that has a tributary area more than 30 percent of the total area of the structure’s floor(s) and roof(s) has been reduced more than 20 percent from its predamage condition, and the remaining capacity of such affected elements, with respect to all dead and live loads, is less than 75 percent of that required by the International Building Code for new buildings of similar structure, purpose and location.

3. The capacity of any structural component carrying snow load, or any group of such components, that supports more than 30 percent of the roof area of similar construction has been reduced more than 20 percent from its predamage condition, and the remaining capacity with respect to dead, live and snow loads is less than 75 percent of that required by the International Building Code for new buildings of similar structure, purpose and location.


[BS] SUBSTANTIAL DAMAGE. For the purpose of determining compliance with the flood provisions of this code, damage of any origin sustained by a structure whereby the cost of restoring the structure to its before-damaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred.

[BS] SUBSTANTIAL IMPROVEMENT. For the purpose of determining compliance with the flood provisions of this code, any repair, alteration, addition, or improvement of a building or structure, the cost of which equals or exceeds 50 percent of the market value of the structure, before the improvement or repair is started. If the structure has sustained substantial damage, any repairs are considered substantial improvement regardless of the actual repair work performed. The term does not, however, include either of the following:

 

[Yankee Chronicler]

Substantial structural damage certainly would be applicable. Nothing in the definition of substantial structural damage limits it to flood damage.

2021 Texas Building Code (per UpCodes):



The definition of "Substantial Damage" you quoted above also appears in the Texas Building Code:



While this starts off by saying "For the purpose of determining compliance with the flood provisions of this code" [which I have not investigated], it then says "damage of any origin sustained by a structure ..." So it doesn't appear that this is limited to flood damage. Here's what the 2021 IEBC Commentary says about this definition:

 

[Wooly]

Staggered studs and “air gap” are typically sound and not fire related….

Correct but oddly enough studs back to back are better for sound than having them staggered. Staggering is better for fire. (studs that is)

 

[Yikes]

Correct but oddly enough studs back to back are better for sound than having them staggered. Staggering is better for fire. (studs that is)

That really depends on all the other components in the wall assembly, and on the path (airborne vs. vibration through materials) and type (frequency) of sound energy.
I've had acoustical engineers tell me that if I have plywood shear panel + resilient channel + gyp board, the 1/2" air gap in the RC will cause the the drywall to act like a drum head, making the sound seem louder. In that scenario, you might be better off with staggered studs and no RC, than a single stud (back to back) with a plywood/RC/gyp board drum.

Regarding fire safety, the additional bearing studs add to structural stability, but also increase combustible surface area within the cavity. The cavity it self requires draft stops to compartmentalize the fire, whereas a single stud wall compartmentalizes itself into separate bays.

 

[SCBO1]

Look at USG wall assemblies and check with the municipality to see if they require an STC rating.

Not sure about using the IEBC, the muni has to adopt it to allow it.