Unlike wall anchor applications, in a stitching tie application the helical tie is used to stabilize brickwork by transferring in- and out-of-plane shear and bending forces across an existing crack. What are common helical stitching tie applications? By intermittently alternating installation angles (0 o, 45 o, 0 o, -45 o, etc.) the tie promotes more monolithic behavior of the wall. In this application, the wall tie is used to attach wythes of brick to one another in an effort to stabilize the wall. However, this provision is not relevant for helical anchors since they are installed into a drilled hole, rather than embedded into a wet mortar joint.Īpplication #2: Stabilizing multiple-wythe brick walls Prescriptive anchors also require bed joints to be at least twice the thickness of the embedded anchor. Around openings larger than 16″ in either dimension: Additional perimeter anchors at maximum 36″ spacing within 12″ of the opening.A maximum anchor spacing of 32″ horizontal and 25″ vertical, and.At least one anchor for each 3.5 ft 2 of wall area, and.In addition, many Designers also follow the detailing practice for prescriptive anchored veneer in Section 6.2.2.5.6 that prescribes the following:
#Hilti anchors for cmu wall code#
However, a rational calculation of required spacing given the demand load can be easily calculated using ACI 530 (Building Code Requirement and Specifications for Masonry Structures), Section 6.2, and test data with an appropriate factor of safety. design standards for the use and qualification of helical wall ties. Thereby, helical anchors allow the repair to be both efficient and inconspicuous when completed. This allows the hole to be patched and concealed with a color matching material. Some helical wall ties, like the Heli-Tie, use an installation tool that countersinks the tie below the surface of the brickwork. As it is driven, the fins of the helical tie tap into both the masonry and backup material and provide an expansion-free connection that will withstand tension and compression loads. Then the helical tie is placed in an installation tool and driven into the pre-drilled hole. Image 1: Installing a helical tie.Ī pilot hole is drilled through the existing brick wall and any air gap into the backup material. Helical ties are an economical solution that can be installed directly through a brick façade into various backup materials such as solid concrete, CMU block, and even wood or metal studs. The need for this type of reinforcement arises when pre-existing wall anchors were never installed, were inadequately spaced or have corroded away over time. In a wall anchor application, the helical tie is used to stabilize the façade by transferring out of plane façade forces through the anchor into the backup material. What are common helical wall tie applications?Īpplication #1: Anchoring building façades to structural members Helical ties can be used to retrofit and stabilize brickwork in two common applications: 1) Wall anchor applications, and 2) Stitching tie applications. Since helical ties are typically used in building façades, they are generally made from stainless steel in order provide the necessary corrosion resistance.
![hilti anchors for cmu wall hilti anchors for cmu wall](https://images.homedepot-static.com/productImages/bb1edfb6-7bb7-4d85-9512-b6adeb4871b2/svn/hilti-masonry-concrete-anchors-66139-64_1000.jpg)
The benefit of this feature is less axial deflection due to a propensity for normal helix shape to “uncoil” under tension load. The design of the Simpson Strong-Tie Heli-Tie wall tie also incorporates a large core diameter in order to provide higher torsional capacity.
![hilti anchors for cmu wall hilti anchors for cmu wall](https://images.homedepot-static.com/productImages/92b0fa87-fc86-4277-8509-6dae30fda5e3/svn/hilti-masonry-concrete-anchors-3575547-64_600.jpg)
This post introduces these two types of helical ties, which might be just what you need for your next brick restoration project.Ī helical tie is made by twisting a metal profile into the shape of a helix. However, often brickwork can be restored and strengthened using helical ties such as Simpson Strong-Tie® Heli-Tie™ wall ties and stitching ties. What do you do when brickwork is in bad condition? Depending on what state the brickwork is in, a tear-down may be called for.