FIELD

The inventions described in this specification relate to foam wall structures that can be particularly desirable for use in buildings constructed in regions prone to high winds and/or seismic activity.

BACKGROUND

Racking strength is an important property in wall panels, as it reflects the ability of a wall to resist movement and keep structures upright during high wind and/or seismic events. A very common approach to achieving the required design value for racking strength in residential construction is to use 2×4 or 2×6 wood framing sheathed with a wood structural panel, typically oriented strand board (“OSB”). The wood structural panel provides the racking strength to the wall panel because it is located in the plane of the shear force. Fasteners (typically nails) hold the sheathing to the framing and provide the racking strength due to their bending and pullout as the wall is placed under increasing shear. Depositing spray foam insulation into to a stud cavity in a wall panel sheathed with OSB will increase the racking strength of the wall panel.

Relatively recently, insulated wall structures satisfying strict industry insulation requirements have been developed that can be made without excessive material and labor costs. According to one proposal, a foam wall structure includes a foam panel, such as a faced polyisocyanurate panel, attached to at least a portion of a front frame surface, such that the faced polyisocyanurate panel and frame members define one or more voids within the frame; and a foam layer received within at least a portion of one of the voids within the frame, wherein the foam layer adheres to at least a portion of the faced polyisocyanurate panel.

Such foam wall structures can provide many benefits. They can exhibit high racking shear strength and excellent thermal resistance. Moreover, they can be fabricated in a controlled, possibly highly automated, manufacturing facility that is away from the construction site, thus increasing the likelihood of consistent results/performance, all while reducing labor and material costs.

Particularly in regions prone to high winds and/or seismic activity, however, it is desirable that wall structures be particularly resistant to racking shear forces. Nevertheless, for ease of construction, the overall thickness of the wall structure should be maintained without sacrificing the amount of insulation used, thereby maintaining a wall's thermal resistance properties. The inventions described in this specification were made in view of the foregoing.

SUMMARY

In certain respects, the specification relates to wall structures. These wall structures comprise: (a) a frame comprising: (i) a first member; (ii) a second member spaced apart from the first member; and (iii) connecting members extending between the first member and the second member, wherein the first member, the second member, and the connecting members each comprise a front surface and a rear surface that form a front frame surface and a rear frame surface; (b) a sheet metal sheathing having a thickness of 0.18 to 3.74 mm (0.007 to 0.147 inch) overlying the front frame surface such that the sheet metal sheathing, the first member, the second member, and the connecting members define a cavity; (c) a foam panel overlying the sheet metal sheathing; and (d) a foam layer disposed within the cavity, wherein the foam layer adheres to the sheet metal sheathing.

In other respects, this specification relates to wall structures that comprise: (a) a frame comprising: (i) a first member; (ii) a second member spaced apart from the first member; and (iii) connecting members extending between the first member and the second member, wherein the first member, the second member, and the connecting members each comprise a front surface and a rear surface that form a front frame surface and a rear frame surface; (b) a sheet metal sheathing having a thickness of 0.18 to 3.74 mm (0.007 to 0.147 inch) overlying the front frame surface such that the sheet metal sheathing, the first member, the second member, and the connecting members define a cavity; (c) a foam panel overlying the sheet metal sheathing, the foam panel comprising a facer on at least a rear face of a core foam layer, wherein the facer is different from the steel sheet metal sheathing; and (d) a foam layer disposed within the cavity, wherein the foam layer adheres to the sheet metal sheathing.

In still other respects, this specification is directed to methods for manufacturing a wall structure. These methods comprise depositing a foam-forming material into a cavity of the wall structure so that the foam-forming material forms a foam layer that adheres to a rear surface of a sheet metal sheathing that has a thickness of 0.18 to 3.74 mm 0.007 to 0.147 inch), wherein the sheet metal sheathing overlies a front surface of a frame of the wall structure, the frame being formed by a front surface of a first member, a front surface of a second member that is spaced apart from the first member, and a front surface of connecting members extending between the first member and the second member and the sheet metal sheathing is fastened to the front frame surface such that the sheet metal sheathing, the first member, the second member, and the connecting members define a cavity; and wherein a foam panel overlies the sheet metal sheathing.

The present specification also relates, among other things, buildings comprising such wall structures.

