Structural Backup

What & Why

What & Why

The structural backup of the building system is designed to support floor and roof loads and to resist lateral wind loads and seismic movement. The exterior veneer is not structural and is connected to the structural backup via wall ties and transfers some wind load to the backup.

Backup Types

Backup Types

Concrete masonry/Concrete block: Concrete Masonry Unit (CMU) walls are constructed with vertical steel reinforcement bars grouted in the CMU cells. The spacing and size of the bars is dependent on the structural performance requirements of the wall.

• Masonry Details B-VC.R.00.1A Veneer w/ CMU Backup Typical Wall Section
• Building Code Requirements for Masonry Structures
• Reinforced Concrete Masonry Composite Walls
• Multiwythe Concrete Masonry Walls
• Structural Design of Unreinforced Composite Masonry
• Designing Concrete Masonry Walls for Wind Loads
• Strength Design Provisions for Concrete Masonry
• Loadbearing Concrete Masonry Wall Design
• Design and Construction of Dry-Stack Masonry Walls

Brick masonry: Unreinforced solid brick masonry, 2 wythes or greater, can function as structural backup, although this is a rare construction type. Reinforced brick masonry as structural backup requires a minimum brick size to allow insertion of steel reinforcement and grout.

• Brick Masonry Bearing Walls
• Brick Masonry Bearing Walls - Shear Design
• Brick Masonry Bearing Wall Construction
• Brick Masonry Bearing Wall Detailing

Reinforced concrete: The connection of the veneer to reinforced concrete can be achieved by veneer ties anchored to the concrete or by a dovetail tie and slot system cast integrally into the concrete wall.

Steel Stud: Steel stud construction is used in conjunction with structural steel or reinforced masonry and is not structural backup itself. Veneer anchors are secured to the backup wall through flashings, water resistive barriers and sheathing directly into steel studs.

Wood Stud: Veneer anchors are secured to the backup wall through flashings, water resistive barriers and sheathing directly into wooden studs.

• The 10 Major Items to Consider with Brick on Wood Frame Construction
• Supporting Exterior Brick Veneer on Wood Construction

Performance: Structural, Energy, Sound, Fire

Performance: Structural, Energy, Sound, Fire

• Heat Transmission of Brick Masonry Walls
• Energy Code Compliance of Brick Masonry Walls
• Fire Resistance of Brick Masonry
• Fire Resistance Rating of Concrete Masonry Assemblies
• Increasing Fire Resistance of Concrete Masonry
• Evaluating Fire-Exposed Concrete Masonry Walls
• Calculating Fire Ratings Tool
• Sound Insulation - Clay Masonry Walls
• Sound Transmission Class Ratings for Concrete Masonry Walls
• Noise Control with Concrete Masonry
• Determining STC Ratings for Masonry Wall Systems