RAP-TIE SYSTEM
The Rap-Tie (Rod Adjustable Plate Tie) system consists of an L-Plate (a vertically orientated L-shaped plate), a V-Tie™ (a V-shaped wire), and an Insulation Support (optional, but recommended). See Figures 1, 2 and 3.
Lateral loads applied to the masonry veneer are transferred through the V-Tie™ to the L-Plate which bears against, and is fastened to, the structural backing. Attachment may be directly to a steel stud, or by surface mounting to a sheathing over a steel stud as shown in Figures 4 and 5, respectively.
Requirements for the structural integrity and moisture protection of any intervening material in the tie load-path, such as a sheathing, are contained in CSA Standard A370, “Connectors for Masonry”, ACI 530.1/ASCE 6/TMS 602 “Building Code Requirements for Masonry Structures” and the International Codes (International Building Code and International Residential Code). The holes along the outboard end of the L-Plate through which the V-Tie™ is inserted provide a positive connection, without the possibility of V-TieTM disengagement during construction and in-service (in accordance with requirements in CSA A370 and ACI 530.1/ASCE 6/TMS 602), and permit up to 36 mm (1.4”) of in-situ vertical adjustment so that a bed joint in the outer wythe will always be coincident with the V-Tie™.
The Insulation Support, which is inserted over the end of the L-Plate and restrained by the V-Tie™, is optionally used to securely and mechanically fix cavity insulation in place.
The Rap-Tie can accommodate a range of insulation thicknesses from 0 to 102 mm (0 to 4”), and air space widths of 25 mm (1”) and greater. The L-Plate has sufficient length to accommodate the thickness of the cavity insulation, and further extends 18 mm (0.7”) into the air space to expose its leading edge and facilitate in-situ placement of the V-Tie™ and optional insulation support. The V-Tie™ is inserted through the appropriate hole along the leading edge of the L-Plate coincident with the mortar bed joint so as to extend horizontally and normally to the structural backing without reducing tie capacity. The legs of the V-Tie™ are positioned along the centreline of the veneer within the placement tolerances permitted by the building code having jurisdiction. Adjustment normal to the wall is facilitated by selecting an appropriate length of V-Tie™.
RAP-TIE COMPONENTS
L-Plate: The L-Plate is manufactured from 16 gauge sheet steel
(1.367 mm [0.0538”] minimum base steel thickness) and is available in both hot-dip galvanized finish and stainless steel. The weight of hot-dip galvanized finish is not less than 460 g/m2/side (1.5 oz/ft.2/side), and satisfies the requirements of CSA A370 (which references ASTM A123), ACI 530.1/ASCE 6/TMS 602 (which references ASTM A153, Class B) and the International Codes (which reference ASTM A153, Class B). The incorporation of holes through the body of the L-Plate minimizes thermal conductivity through the tie system.
The overall length of the L-Plate is 18 mm (0.7”) longer than the specification length (L). The specification length is the total distance between the exterior face of the insulation and the exterior face of the component of the structural backing to which the L-Plate is fastened/bears. The L-Plate is available in specification lengths (L) of 0 (0”), 28 (1.1”), 41 (1.6”), 54 (2.1”), 67 (2.6”), 79 (3.1”), 92 (3.6”) and 105 (4.1”) mm. Intermediate sizes are also available.
V-Tie™: The V-Tie™ is manufactured from 4.76 mm (0.19”) diameter wire and is available in both hot-dip galvanized finish and stainless steel. The weight of the hot-dip galvanized finish is not less than 460 g/m2 (1.5 oz/ft.2) and satisfies the requirements of CSA A370 (which references ASTM A123), ACI 530.1/ASCE 6/TMS 602 (which references ASTM A153, 458 g/m2) and the International Codes (which reference ASTM A153, Class B, 458 g/m2).
The V-Tie™ is available in a variety of standard lengths to accommodate different specified thicknesses of masonry veneer and design widths of air space. Varying lengths of V-Tie™ also facilitate in-situ adjustment normal to the structural backing (to accommodate construction tolerances) where the constructed width of air space differs from the design width of air space. Standard lengths of V-Tie™ include 60 mm (2.4”), 80 mm (3.1”), 100 mm (3.9”), 120 mm (4.7”), 140 mm (5.5”), 160 mm (6.3”), 180 mm (7.1”), 200 mm (7.9”), 225 mm (8.9”) and 250 mm (9.8”).
Insulation Support: The Insulation Support is manufactured from poly ethylene. It is pressed over the outboard end of the L-Plate tightly against the cavity insulation to prevent the insulation from separating from the structural backing/air barrier. The friction fit between the Insulation Support and the L-Plate restrains the insulation during construction which is commonly installed in advance of the exterior masonry wythe. Subsequent installation of the V-Tie™ sandwiches the Insulation Support between the insulation and the V-Tie™, thereby locking the Insulation Support in-place and ensuring a reliable and permanent insulation support system.
RAP-TIE STRUCTURAL COMPOSITE ACTION
In most applications, the Rap-Tie is designed to simply transfer the lateral load from the exterior masonry wythe (the veneer) axially to the structural backing, and a single fastener will usually prove adequate. However, by using two fasteners to attach the L-Plate to the structural backing, shear forces as well as axial forces can be resisted by the Rap-Tie to provide composite action between the masonry veneer and the structural backing. The entire wall thickness, including both veneer and structural backing, becomes effective in resisting lateral loads, offering reduced lateral deflections and increased lateral resistance (see FERO Stud Shear™ Connector or Block Shear™ Connector literature). A Rap-Tie can be used for retro-fitting masonry veneer systems where reducing lateral deflection of the steel stud structural backing is a required intervention. (Use the FERO Shear Truss program to evaluate forces in the assembly).
