zip shething in type IIB construction

[Tim Mailloux]

I have used zip sheathing on several IIB buildings in the past. These were all steel moment fame structures with non load bearing light gauge metal stud exterior walls. I used the insulated Zip sheathing to get continuous insulation and a nail base for the exterior siding all one product. I based my usage on the material base on my interpretation of 601.1 item #13 and 1405.5.

Section 601.1 item #13 which allows for combustible materials in type #I and Type #II buildings in “Combustible exterior wall coverings, balconies and similar projections or oriel windows in accordance with chapter 14”

Exterior wall covering definition: A material or assembly of materials applied on the exterior side of exterior walls for the purpose of providing a weather-resisting barrier, insulation or for aesthetics, including but not limited to, veneers, siding, exterior insulation and finish systems, architectural trim and embellishments such as cornices, soffits, facias, gutters and leaders.


1405.5 Wood veneers. Wood veneers on exterior walls of buildings of Type I, II, III and IV construction shall be not less than 1 inch (25 mm) nominal thickness, 0.438-inch (11.1 mm) exterior hardboard siding or 0.375-inch (9.5 mm) exterior-type wood structural panels or particleboard and shall conform to the following:

1. The veneer shall not exceed 40 feet (12 190 mm) in height above grade. Where fire-retardant-treated wood is used, the height shall not exceed 60 feet (18 290 mm) in height above grade.​

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2. The veneer is attached to or furred from a noncombustible backing (metal studs) that is fire-resistance rated as required by other provisions of this code.​

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3. Where open or spaced wood veneers (without concealed spaces) are used, they shall not project more than 24 inches (610 mm) from the building wall.​

However it was just pointed out to me by a co-worker that the ICC report for Zip Sheathing states that zip sheathing can only be used in Type V construction. Whats the opinion of everyone here?

 

[RLGA]

In my opinion, the sheathing is part of the wall construction and is not considered part of the exterior wall covering, which I consider to be anything that is attached to the wall construction outside of the sheathing.

 

[Tim Mailloux]

In my opinion, the sheathing is part of the wall construction and is not considered part of the exterior wall covering, which I consider to be anything that is attached to the wall construction outside of the sheathing.

so your in the not allowed camp in type IIB construction? What about 1405.5?

 

[RLGA]

so your in the not allowed camp in type IIB construction? What about 1405.5?

Read the definition of "veneer" in Chapter 2:

"A facing attached to a wall for the purpose of providing ornamentation, protection or insulation, but not counted as adding strength to the wall."​

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Sheathing is not a facing and is typically required for lateral stability and strength of the wall.

 

[steveray]

602.2 Types I and II. Types I and II construction are those
types of construction in which the building elements listed in
Table 601 are of noncombustible materials, except as permitted
in Section 603 and elsewhere in this code.

So if it is a nonbearing wall you go to T602

603.1 Allowable materials. Combustible materials shall be
permitted in buildings of Type I or II construction in the following
applications and in accordance with Sections 603.1.1
through 603.1.3:

This is where it gets dicey and you can use some FRTW

Our State has typically sided on the "siding blocking" approach.....Maybe via the "exterior wall covering" approach.....#13 or 14...

Mind you , you are also creating a concealed combustible space that now needs to be fireblocked and potentially sprinklered....

Does the ICC report say "can only be used as STRUCTURAL sheathing in V"?

 

[Tim Mailloux]

Read the definition of "veneer" in Chapter 2:

"A facing attached to a wall for the purpose of providing ornamentation, protection or insulation, but not counted as adding strength to the wall."​

​

Sheathing is not a facing and is typically required for lateral stability and strength of the wall.

the building has structural steel moment framed structure. The exterior walls are non structural and are just to keep the weather out. In this instance the plywood sheathing is a nail base (aka blocking) to attached the exterior finishes to. The exterior finish is going to be a random metal panel with concealed clips that need to get attached to wood sheathing or some sort of studs. Becuase the panels are a random size they will not always fall on a stud, hence the needs to wood sheathing.

 

[steveray]

Is it 1"?

1404.5 Wood veneers. Wood veneers on exterior walls of
buildings of Type I, II, III and IV construction shall be not
less than 1 inch (25 mm) nominal thickness, 0.438-inch (11.1
mm) exterior hardboard siding or 0.375-inch (9.5 mm) exterior-
type wood structural panels or particleboard and shall
conform to the following:

 

[Tim Mailloux]

Is it 1"?

1404.5 Wood veneers. Wood veneers on exterior walls of
buildings of Type I, II, III and IV construction shall be not
less than 1 inch (25 mm) nominal thickness, 0.438-inch (11.1
mm) exterior hardboard siding or 0.375-inch (9.5 mm) exterior-
type wood structural panels or particleboard and shall
conform to the following:

no its 5/8" thick...but you missed this part "0.375-inch (9.5 mm) exterior-type wood structural panels or particleboard and shall conform to the following"

 

[Tim Mailloux]

Steveray - would you allow it in your jurisdiction?

 

[steveray]

I don't love it, and would probably touch base with OSBI, if not rip into commentary a bit more, but the argument you present is valid...

 

[RLGA]

I would accept it if it complied with Section 603.1, application 1.2, provided the sheathing is FRT and the walls are nonbearing.

 

[steveray]

And for clarity...."bearing" has nothing to do with shear.....as far as the IBC is concerned......Maybe its time for a full rewrite of Ch. 6...

BEARING WALL STRUCTURE. A building or other structure in which vertical loads from floors and roofs are primarily supported by walls.

 

[Manific]

Bro, I think that the sheathing is a part of the wall construction. It can't be considered as the part of the exterior wall covering. It's only something that is attached to the wall construction outside the sheathing. In general, zip system sheathing can be used in Type III construction only as a roof sheathing. That's all I can tell you here. I wanted to ask for your suggestions as well. I need to purchase or even rent a scissor lift. Do you know any reliable places where I can find it?