Brick ties under the 2021 International Residential Code (IRC) are corrosion-resistant metal ties embedded in the mortar and fastened to the wall studs. Each tie may carry no more than 2.67 square feet of wall, at no more than 32 inches horizontally and 24 inches vertically (Section R703.8.4.1).
A brick tie is the small metal strap or wire that connects brick or stone veneer to the framed wall behind it. The veneer carries only its own weight and sits on the foundation, so the ties hold it upright and resist wind and seismic push, and the airspace behind lets water drain out.
Key facts
- Masonry veneer must be anchored to the supporting wall studs with corrosion-resistant metal ties that extend at least 1-1/2 inches into the veneer, with at least 5/8 inch of mortar or grout cover to the outside face (2021 IRC Section R703.8.4).
- Each tie supports no more than 2.67 square feet of wall area, spaced no more than 32 inches on center horizontally and 24 inches on center vertically (2021 IRC Section R703.8.4.1).
- In Seismic Design Category D0, D1 or D2, in townhouses in Seismic Design Category C, or in wind areas above 30 pounds per square foot pressure, each tie supports no more than 2 square feet (2021 IRC Section R703.8.4.1, Exception).
- Openings larger than 16 inches in either dimension need extra ties within 12 inches of the opening, spaced no more than 3 feet on center (2021 IRC Section R703.8.4.1.1).
- Veneer over a wood or steel backing is limited to the first story above grade plane and to 5 inches in thickness, unless an exception for Table R703.8(1) or R703.8(2) applies (2021 IRC Section R703.8).
- Weepholes in the outside wythe must be at least 3/16 inch in diameter, no more than 33 inches on center, immediately above the flashing (2021 IRC Section R703.8.6).
What size and type of brick tie does the IRC require?
The IRC accepts two tie families: strand wire and corrugated sheet metal.
Strand wire ties must be at least No. 9 U.S. gage (0.148 inch) wire with a hook embedded in the mortar joint. Sheet metal ties must be at least No. 22 U.S. gage, 7/8 inch wide and corrugated (2021 IRC Section R703.8.4.1). Table R703.8.4(1) adds the larger W2.8 (0.187 inch) wire for wider cavities.
What does Table R703.8.4(1) require on wood studs?
Table R703.8.4(1) pairs each tie type on a wood stud backing with a minimum fastener and an airspace.
2021 IRC Table R703.8.4(1), tie attachment and airspace requirements, wood stud backing rows only.
| Tie | Minimum tie fastener | Airspace |
|---|---|---|
| 22 gage (0.0299 inch) by 7/8 inch corrugated sheet metal | 8d common nail (2-1/2 by 0.131 inch) | Nominal 1 inch between sheathing and veneer |
| W1.7 (No. 9 gage, 0.148 inch) adjustable wire, hook embedded in mortar joint | 8d common nail (2-1/2 by 0.131 inch) | Minimum nominal 1 inch between sheathing and veneer; maximum 4-5/8 inches between backing and veneer |
| W2.8 (0.187 inch) adjustable wire, hook embedded in mortar joint | 8d common nail (2-1/2 by 0.131 inch) | Greater than 4-5/8 inches between backing and veneer; maximum 6-5/8 inches |
In Seismic Design Category D0, D1 or D2 the minimum tie fastener becomes an 8d ring-shank nail of the same 2-1/2 by 0.131 inch size (footnote c). The table also has cold-formed steel stud rows that use No. 10 screws, which this article does not reproduce.
Adjustable wire ties have extra detail requirements. W1.7 ties need at least one pintle leg of wire size W2.8 with a maximum offset of 1-1/4 inches (footnote d). W2.8 ties need at least two pintle legs with the same maximum offset, and the distance from the inside face of the brick to the end of the pintle may be at most 2 inches (footnote e). Footnote f lists the backing attachment components allowed for adjustable ties.
How many brick ties per square foot of wall?
Each tie may support no more than 2.67 square feet of wall area, and the spacing limits are 32 inches horizontally and 24 inches vertically (2021 IRC Section R703.8.4.1). 2021 IRC Section R703.8.4.1, brick tie area and spacing limits.
| Condition | Maximum wall area per tie | Maximum spacing |
|---|---|---|
| Standard | 2.67 square feet | 32 inches horizontal, 24 inches vertical |
| Seismic Design Category D0, D1 or D2; townhouses in Seismic Design Category C; wind areas above 30 psf pressure | 2 square feet | Same spacing limits apply |
The code gives no different spacing for the 2 square foot case, so confirm the final tie layout with your building department. Ties are fastened to studs in this method, so see stud spacing for the layout they land on.
Where do extra brick ties go around openings?
Add ties around any wall opening greater than 16 inches in either dimension, spaced no more than 3 feet on center and placed within 12 inches of the opening (2021 IRC Section R703.8.4.1.1).
The framing side of the same opening is covered in the header size chart. Veneer above an opening needs its own support: Section R703.8.3 requires noncombustible lintels with at least 4 inches of bearing, and the veneer may not carry any vertical load other than its own weight.
Can brick ties go straight into the sheathing?
Yes, in one limited case. Where the tie attachment is fastened to wood structural panel of at least 7/16 performance category, through insulating sheathing not greater than 2 inches thick, use Table R703.8.4(2), and fastening to the studs behind the sheathing is then not required (2021 IRC Section R703.8.4).
Table R703.8.4(2), "Required brick tie spacing for direct application to wood structural panel sheathing", gives vertical and horizontal tie spacing by fastener type and size, design wind speed and exposure category. Its footnotes set further conditions: building height of 30 feet or less, panel specific gravity of 0.42 or greater, foam sheathing of at least 15 psi compressive strength, and fastener tips passing through the panel by at least 1/4 inch. This article does not reproduce the values, so read the table in the code itself. The panel side is covered in wall sheathing.
How much airspace does brick veneer need?
Brick veneer needs the airspace listed in Table R703.8.4(1): nominal 1 inch for corrugated ties, and between 1 inch and the stated maximum for wire ties. Wider cavities need the heavier W2.8 wire.
The airspace is a drainage space and may contain mortar from construction (Table R703.8.4(1), footnote b). Section R703.8.4.2 lets grout fill the airspace instead, but a water-resistive barrier is then required over the studs or sheathing.
Drainage depends on two more details. Flashing goes beneath the first course of masonry above finished ground level, and at other points of support such as structural floors, shelf angles and lintels (Section R703.8.5, with Section R703.4). Weepholes sit immediately above that flashing (Section R703.8.6).
How tall can brick veneer be over a wood-framed wall?
Over wood or cold-formed steel backing, veneer is limited to the first story above grade plane and to 5 inches in thickness, with exceptions that raise the allowed height (2021 IRC Section R703.8).
Table R703.8(1) covers Seismic Design Categories A, B and C. Every row lists a maximum veneer height of 30 feet above a noncombustible foundation, a maximum nominal thickness of 5 inches and a maximum weight of 50 psf, and footnote a allows an additional 8 feet for gable end walls. The table itself shows which stories each row covers.
2021 IRC Table R703.8(2), detached one- and two-family dwellings in Seismic Design Categories D0, D1 and D2, wood framing.
| Seismic Design Category | Maximum nominal veneer thickness | Maximum veneer weight |
|---|---|---|
| D0 | 4 inches | 40 psf |
| D1 | 4 inches | 40 psf |
| D2 | 3 inches | 30 psf |
Table R703.8(2) also sets veneer heights by story count, and cripple walls are not permitted in these categories. Wall bracing for masonry veneer on wood framing is in Section R602.10.
What does the wood frame have to provide?
The frame has to give the ties something solid to bite into and has to carry nothing it was not designed for.
- Studs at known locations. Ties are fastened to the supporting studs, so the stud layout drives the tie layout. See wall framing basics.
- A foundation ledge. Veneer normally sits on the foundation. Veneer weighing 40 psf or less may be supported on wood or cold-formed steel construction in some cases, but not in Seismic Design Categories D0, D1 and D2, and the supporting members must be designed to limit deflection to 1/600 of the span (Section R703.8.2). See the stem wall guide.
- Flashing and drainage detail at the base. The flashing sits above the foundation wall or slab, and the base of the wood wall is covered in the sill plate guide.
Putting it on a drawing
A framing plan does not normally show ties, but the wall notes should name the tie type, fastener and airspace so a reviewer can check them against Table R703.8.4(1).
Summary
Under the 2021 IRC, brick veneer is tied to the studs with corrosion-resistant ties, each covering no more than 2.67 square feet (2 square feet in higher seismic or wind conditions), at no more than 32 inches horizontally and 24 inches vertically. Extra ties go within 12 inches of openings larger than 16 inches. Table R703.8.4(1) sets the fastener and airspace, and Table R703.8.4(2) covers direct fastening to sheathing. The adopted code edition and local amendments govern, and manufactured anchor systems follow the manufacturer's instructions.
Framing Plan is a preliminary drawing aid and does not draw veneer or check ties. It draws walls, openings, beams and joist layouts and exports PNG, PDF and DXF. Open the framing studio to lay out the wall and opening geometry that your veneer ties will have to work around.