September 2005 - Composite Wall is Stronger, Easier to Install
By Mandi Harding, FCA Executive Director

Attendees at last month’s FCA quarterly luncheon were educated on the strengths and benefits of using Simpson Strong-Tie’s new Steel Strong-Wall by Engineering Manager Ricardo Arevalo.

Arevalo emphasized five highlights when considering the Steel Strong-Wall:

• Stronger Wall: An engineered composite of steel and wood, this new addition to the Strong-Wall line features allowable loads that are two to three times higher than the original Strong-Wall.
• Unique Design: The unique steel design resists distortion of the center section and results in sustained vertical load capacity.
• Simplified Installation: Feedback from contractors resulted in the building industry’s easiest to install shear wall, including pre-attached wood studs, two easily accessible anchor bolts, fewer top-of-wall screws and SDS screws. Easy access at top and bottom for quick installation.
• Contractor friendly: Easy to use reversible template for concrete contractors and predrilled holes where electricians need them for wiring.
• Narrow Garage Wall Solution: With walls as narrow as 12” Simpson Strong-Tie has solved the problem of wider code required walls at garage front.
• Support and Service: Simpson provides the best engineering technical support and experienced field representation available.
  

Arevalo discussed specific features to the Steel Strong-Wall. He said the maximum shim height between the Steel Strong-Wall and the top plates or headers is 7/8-inch, using SDS ¼  x 3 ½ screws, which are provided. The strong-wall also offers strategically placed quarter-inch holes to attach electrical boxes and blocking or framing and pre-attached wood studs. Besides boasting holes predrilled for wiring, the strong-wall comes standard with additional 1 1/8-inch diameter holes allowed in stud at each obround hole. And mounting becomes a snap when the Steel Strong-Wall is placed over the anchor bolts and the nuts provided are installed said Arevalo.

Arevalo also noted that the walls may be used in 2 x 6 wall framing, but in order to do so the Steel Strong-Wall needs to be installed flush to one face of framing and add furring to the opposite side.

The Engineer of Record is responsible for concrete design and is permitted to modify details for specific conditions including: shear transfer, out of plane loading effect, increased overturning and drift due to additional height, reminded Arevalo.

Simpson currently offers five wall models installed on concrete, the SSW12, SSW 15, SSW 18, SSW 21 and SSW 24.
Arevalo next outlined the wall’s height profile. He said the heights range 7 to 13 feet and that the 7 foot wood walls are equal to 78 inches and the 8foot Steel Strong-Wall is equal to 80 inches high.

• SSW 12  -  7 ft to 10 ft
• SSW 15  -  7 ft to 12 ft
• SSW 18  -  7 ft to 13 ft
• SSW 21  -  7 ft to 13 ft
• SSW 24  -  7 ft to 13 ft

In terms of widths and thickness, Arevalo said the Steel Strong-Wall equals 12 to 24 inches and again includes the pre-attached wood studs which enable the quick installation of interior and exterior wall finishes. Arevalo stated that in terms of wall thickness, 7 to 10 foot walls are 3 ½ inch thick (2 x 4) and 11 to 13 foot walls are 5 ½-inch thick (2 x 6.) He also said that stud replacement is ok in the Steel Strong-Wall.

“There are also a few templates worth mentioning,” said Arevalo. “First there is the usual reversible template for both interior and exterior conditions and then for special conditions Simpson Strong-Tie offers the brick ledge template and the panel form template that mounts directly to the concrete.”

Arevalo stressed that ¾-inch anchor bolts were required for the 12 inch wall and 1 inch anchor bolt for the 15 to 24 inch wall, and no washers were needed. Diagrams were provided to explain the appropriate shim detail requirements depending on whether the Steel Strong-Wall was being utilized in a 2x Flat Shim Block, 4x Shim Block, a Rake wall or a Cripple Wall.

Arevalo wrapped up his 45 minute presentation with a photo and description of how the new Simpson Strong-Tie product under testing produced only a flange buckling versus a complete panel buckling.

For more information on the Simpson Steel Strong-Wall or related education contact Simpson Strong-Tie’s Mike Wagner at 491-9393.