How Many Wall Ties Does The BOCA National Building Code Require?

BOCA 1405.5.3 states that wall ties must be installed at not less than one per three square feet of wall area, not more than 32 inches apart horizontally, and not more than 16 inches apart vertically.

Typically, wood stud framing is on 16" centers, so the limit of 32" on center horizontally would permit one tie in every other stud, but the one tie per three square feet requirement would then limit the vertical spacing to 13"+, which would require that ties be installed in every fourth course of brick, which may unneccesarily slow down the mason. Therefore, in order to comply with BOCA and maximize mason productivity, it is suggested that a wall tie be attached to each stud (at 16" or 24"o.c.) not to exceed every 16" vertically (6 courses for 2 1/4" high units [modular and standard] and 5 courses for 2 3/4" high units [queen, princess, king, engineer, and norweigan]).

Is Random Nailing Of Wall Ties Prior To The Masons' Arrival On The Jobsite Recommended?

No! Random installation of wall ties without regard to bed joint height serves no purpose. Wall ties are optimally effective when nailed at the level of the bed joint.

If wall ties are installed by framing carpenters or by someone other than the brickmason, an acceptable practice is to nail them on level horizontal lines corresponding to bed joint heights at regular vertical intervals (Compliance with BOCA 1405.5.3 would be achieved by a tie on every stud at 16" vertically). This would permit the ties to be anchored in the same course of brickwork. Ties nailed randomly serve little or no purpose.

If brickmasons install wall ties, follow the same spacing requirements stated above. Tie requirements do not change according to variable properties of brick, such as absorption. Tie installation by competent masons can result in more effective tie strength if the nail is even with the top of the course of brick receiving the tie. If the nail is above or below the top of the course of brickwork receiving the tie, the effectiveness of the tie will be measurably reduced.

What Purpose Do Wall Ties Serve?

Wall ties on wood stud framing serve one purpose:

They transfer lateral forces on the brickwork, primarily wind loads, back to the wood framing.

The action of the wind can produce a lateral force in either the form of pressure or suction on the brickwork, and the ties deliver that load to the framing system which resists the load.

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