Veneer Wall: Brick Veneer/Wood Stud Framing (3+ stories)

• Single-family and multi-family residential, shopping centers and restaurants, low-rise construction
• Use where budget is more important than longevity

• Has the appearance of a solid masonry building but wood framing costs less
• Durable, long-lasting wall system
• Minimal long-term maintenance
• Great design flexibility with many colors, textures and bond patterns available
• Cavity system keeps building interiors dry

• Wood stud construction will flex more than the brick veneer. This can lead to cracks in the brick veneer unless the back-up is designed to strict deflection tolerances.
• Multiple trades involved with this wall system which can make jobsite coordination more difficult.
• Tolerances for wood erection are looser than those for masonry. This can lead to conflicts during veneer construction. Include a larger air space in the cavity to accommodate this.
• Wood studs can rot if water penetrates past the drainage cavity. If the studs rot, this compromises the entire structure.
• There is a potential for mold growth on the sheathing of the cavity unless you use mold-resistant sheathing.

• Backup: 2×4 wood studs at 16” on center
• Veneer: Cored modular clay brick (nominal 4” x 2-5/8” x 8”)
• Sheathing: 5/8” oriented strand board sheathing, nailed to the studs @ cavity; ½” gypsum board @ interior face
• Weather Resistive Barrier: 15-pound building paper, installed in horizontal strips and shingle-lapped 2” with each successive strip
• Cavity: 2-inch air space (1″ open cavity + 1” rigid insulation)
• Insulation: 3.5”-inch batt insulation installed between the studs plus 1-inch rigid extruded polystyrene board in the drainage cavity (Reference: Colorado Masonry Systems Design Guide, Chapter 8, Figure 8-22 (similar))
• Flashing: Self-adhered bitumen flashing paired with metal drip edge (Reference: Colorado Masonry Systems Design Guide, Chapter 6, Shelf Angle Flashing Options, Fig.6-3 (Option 2))
• Masonry Ties: Two-piece adjustable ties attached to the studs that are rigid horizontally and can slip vertically, spaced at 16” x 16” spacing (Reference: Colorado Masonry Systems Design Guide, Chapter 6, Table 6-4)
• Shelf Angle: To support veneer at floor level (if building is more than 30 feet tall)
• Mortar: Type N, Portland cement/lime, plain gray
• Joint finish: Concave tooled

• In areas with high seismic risk, masonry ties and anchors might have special requirements. Check your local building codes.

• Fire Rating of a multi-layered cavity wall = (Rating₁ ^0.59 + Rating₂ ^0.59 + 0.3)^1.7
• The brick by itself has 1-hour fire resistance
• If you need more fire resistance, add layers of Type X gypsum board to the wood studs in the back-up wall.

Reference: BIA Tech Note 16

• 32.6 pounds per square foot
• 27 (brick veneer) + 2 (OSB sheathing) + 1.4 (wood framing) + 2.2 (gypsum board)

• STC = (weight of wall)^0.233 x 21.5
• STC = 48.49 dB

Reference: BIA Tech Note 5A

• R-value: 19.49
• Calculations
  • Outside air                                    0.17
  • 4” brick                                          0.44
  • Air gap                                           0.97
  • 1” extruded polystyrene            5.00
  • Oriented strand board               0.68
  • 3.5” batt insulation                    11.00
  • Gypsum sheathing                      0.45
  • Inside air film                               0.78
  • TOTAL R-value                           19.49

Thermal mass benefit:  Brick Builder Note, Issue 8, April 2018 – Brick & Energy Efficiency
Reference: BIA Tech Note 4
Reference: International Energy Conservation Code, Tables C402.1.3 and C402.1.4

• There are three different pathways to meeting the requirements of the International Energy Conservation Code (IECC). You can use R-values to satisfy the prescriptive limits of Table C402.1.3 of the code. Using R-values requires continuous insulation in the cavity in all Colorado climate zones. Following Table C402.1.4 of the code uses U-values to meet the insulation requirements. This approach does not require continuous insulation in the cavity. A third approach is to use computer software like COMCheck — to prove that the building meets code. Computer software is the most complex, but it is also the most flexible option. It is often the best choice for mass walls.
• Tighten up the tolerances for wood construction to match those for the brick veneer. There can be significant conflicts between the wood erection and the masonry trades.
• Attach windows and doors to the wood studs, NOT to the brick veneer.
• Make sure you have at least ¾” overlap between the door and window jambs and the brick veneer. Install backer rod and sealant at the joints where different materials meet.
• You must use sheathing to face the stud wall at the drainage cavity.
• Use building paper to cover the sheathing or use water resistant sheathing with taped joints.
• Design the wood stud back-up to a deflection limit of L/720 to minimize veneer cracking.
• Be careful supporting brick on wood stud construction. Currently the Building Code limits these applications to situations where no more than 12 vertical feet of masonry is being supported. You will need extra movement joints in the brick veneer to separate brick supported by wood construction from brick supported by the foundation.
• Provide extra clearance between the windowsills and window heads in the brick veneer in 2- or 3-story construction. The wood studs will shrink with age while the brick veneer will grow. This can lead to serious movement issues on multi-story buildings. Surround the windows with backer rod and sealant that can accommodate this anticipated movement. 

• Meet with the general contractor early in the project to make sure the wood framing foreman understands how tight the masonry installation tolerances are.
• Anchor the veneer ties to the studs using galvanized nails or screws. It is not permitted to anchor the ties into the sheathing alone.
• Uses two-piece adjustable ties that can slip vertically but are rigid horizontally.

Flashing

Self-Adhered Flexible Flashing: This tough, flexible flashing strip comes with a removable release liner for easier installation. The liner MUST be removed to allow the sticky layer of the flashing to self-heal around any punctures from nails or screws. If the sticky layer of the flashing is bitumen, hold this flashing at least ½” from the edge of the masonry so that the tar layer does not melt and form ugly black drips on the face of the wall. Bitumen-based flashing is often paired with a metal drip edge which can be exposed to sunlight. This flashing will stick to masonry, concrete, gypsum, wood, or steel.

Base of Wall —Flash Vent Self-Adhering SS Flashing with Drip Edge 

Masonry Anchors & Ties

Barrel Veneer Ties: Designed to minimize thermal transfer. The thickness of the barrel resists bending, and the single screw allows the anchors to be installed quickly. The factory-installed EPDM washers seal the penetration the screw makes in the air/vapor barrier. Using this style of masonry anchor will minimize the amount of tape used to seal joints in the rigid insulation.

H-B 2-Seal™ Thermal Wing Nut Anchor