Veneer Wall: Brick Veneer/Steel Stud Framing

• Schools, offices, commercial and institutional buildings, hotels, shopping centers and restaurants
• Use this wall system where budget is more important than longevity

• Has the appearance of a solid masonry building but steel framing is typically less expensive than a concrete masonry (CMU) back-up wall
• Lighter weight than brick veneer on CMU back-up
• 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

• Steel stud back-up wall 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 steel 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.
• Steel studs can corrode if water penetrates past the drainage cavity or if moisture condenses on the steel.
• Interior drywall surfaces are less robust than CMU walls.  This can lead to vandalism and damage in heavy traffic areas.
• There is a potential for mold growth on the sheathing of the cavity unless you use mold-resistant sheathing.

• Backup: 16-gauge x 6” steel studs at 16″ on center
• Veneer: Cored modular clay brick (nominal 4” x 2-5/8’ x 8”)
• Sheathing: Exterior grade sheathing, screwed to the studs
• Weather Resistive Barrier: Building wrap with 6″ overlap where sheets meet
• Cavity: 2-inch air space (1” open drainage + 1″ rigid insulation)
• Insulation: 6-inch batt insulation installed between the studs plus 1-inch rigid extruded polystyrene in the drainage cavity (Reference: Colorado Masonry Systems Design Guide, Chapter 8, Figure 8-17)
• Flashing: Self-adhered bitumen flashing with 1” 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 screwed into the studs that are rigid horizontally and can slip vertically, spaced at 16” (horizontal) x 16” (vertical) (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 are required to be attached to wire reinforcement embedded in the mortar bed joints of the veneer. Check your local building codes.

• Fire Rating of a multi-layered cavity wall = (Rating₁ ^0.59 + Rating₂ ^0.59 + 0.3)^1.7FF
• The veneer 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

• 32.8 pounds per square foot

• STC = (weight of wall)^0.233 x 21.5
• STC = 50.83 dB

Reference: BIA Tech Note 5A

• R-value: 27.26
• Calculations
  • Outside air film                                 0.17
  • 4” brick                                               0.44
  • Air gap                                                0.97
  • 1” extruded polystyrene                  5.00
  • Gypsum board                                  0.45
  • 6” batt insulation                            19.00
  • Interior air film                                  0.78
  • TOTAL                                               27.26

Thermal mass benefit:  Brick Builder Note, Issue 8, April 2018 – Brick & Energy Efficiency
Reference: BIA Tech Note 4
Reference: Colorado Masonry Systems Design Guide, Chapter 8, Figure 8-19
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.
• Use galvanized hardware and screws to attach veneer ties to the studs. This will minimize potential for corrosion.
• Tighten up the tolerances for steel construction to match those for the brick veneer. There can be significant conflicts between the steel erection and the masonry trades.
• Attach windows and doors to the structural steel studs, NOT to the masonry 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 steel stud wall at the drainage cavity.
• Use building wrap to cover the sheathing or use water resistant sheathing with taped joints.
• Design the steel stud back-up to a deflection limit of L/720 to minimize veneer cracking.
• Shelf angles may not be required for veneer support at every floor line. Cut down on the number of shelf angles to save money and simplify construction. If your brick veneer is less than 30’ above the top of the foundation, it might not need relieving angles at all.

• Meet with the general contractor early in the project to make sure the steel erector understands how tight the masonry installation tolerances are.
• Anchor the veneer ties to the steel studs using galvanized 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 

Roof to Wall Parapet Detail —York 304 SA Self-Adhering Stainless Steel Flashing (view from face of wall)

Roof to Wall Parapet Detail —York 304 SA Self-Adhering Stainless Steel Flashing (view from roof)

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

Double-Pin Stone Anchor: Allows you to tie two capstones to the top of the parapet with each anchor. Drill an over-sized hole in the ends of each piece of the masonry cap. Insert a pin into the fresh mortar and then attach the angle of the anchor to the top edge of the structural wall.

H-B Stone Anchor #433

Cap with Pins

Weld-On Masonry Anchor: A masonry anchor that’s designed to be welded to structural steel members.

H-B Weld-on Ties