ADJUSTABLE BVTS SYSTEM

The Adjustable BVTS (Adjustable Brick Veneer Tie Support) system provides all the benefits of the BVTS system with the added advantages of (i) allowing for vertical differential movement between the masonry veneer and the backup wall system, and (ii) providing tie placement adjustability during construction.

Image Gallery The Adjustable BVTS is specially designed to provide lateral support for masonry veneer on structures where the unsupported height of the veneer is larger than 4 meters (13’), but less than the allowable height of 11 meters (36’) (CSA CAN3-S304-04). The system allows for thermal movement and moisture expansion of the veneer and for frame shortening of the structure.

The Adjustable BVTS system is illustrated in Figure 1.

The adjustability of the system is achieved by placing the AB-Clip (as shown in Figure 3), on top of the BVTS (see Figure 4), and attaching the two components to the backup system with two fasteners. The V-Tie™ (shown in Figure 2), is then threaded through the assembly and placed into a mortar joint during construction of the masonry veneer.

The Adjustable BVTS system is designed to accommodate cavity widths (insulation thickness plus air space) of 25 mm (1") up to 275 mm (10.8").

ADJUSTABLE BVTS COMPONENTS

Every BVTS is constructed of 20 gauge (1.01 mm [0.04"] thick) sheet metal conforming to ASTM Standard A570. Three 6 mm (0.24") diameter holes are provided to facilitate the attachment of the AB-Clip and V-Tie™. BVTS heights of 21 (0.83”), 31 (1.22”), 40 (1.57”), 52 (2”), 65 (2.56”) and 78 mm (3.07”) are available. Figure 1 illustrates the physical dimensions of the available BVTS. BVTS are available in hot dipped galvanized finish (conforming to CSA CAN3-A370-04 and ASTM requirement of 458 g/m²/side [1.5 oz/ft²/side] of zinc coating).

ABVTS 3 The AB-Clip is manufactured from 16 gauge (1.61 mm [0.063”] thick) sheet metal, conforming to ASTM A570. The AB-Clip is available in hot dipped galvanized finish (conforming to CSA CAN3-A370-04 and ASTM A153 requirement of 458 g/m²/side [1.5 oz/ft²/side] of zinc coating).

Rap Tie The V-Tie™ is manufactured from 4.76 mm (0.19”) diameter wire, conforming to CSA Standard G30.3. V-Tie™ lengths of 60 (2.4”), 80 (3.1”), 100 (3.9”), 120 (4.7”), 140 (5.5”), 160 (6.3”), 180 (7.1”), 200 (7.9”), 225 (8.9”) and 250 mm (9.8”) are available. The V-Tie™ is available in hot dipped galvanized finish (conforming to CSA CAN3-A370-04 and ASTM A153 requirement of 458 g/m²/side [1.5 oz/ft²/side] of zinc coating) and stainless steel.

STRUCTURAL PERFORMANCE OF THE V-TIE™

The unique configuration of the V-Tie™ provides for much greater pull-out (or push-out) capacity from the mortar joint of the brick veneer than similar ties currently on the market. The area of mortar effective in providing support to the V-Tie™ is illustrated in Figure 6. The effective mortar for a number of typical ties is also shown in the figure. A comparison of the pull-out capacities of the various tie types is presented in Table 1.

Table 1 Comparison of Tie Pull-Out Capacity in
90 mm (3.5") Brick Application

Tie Type	Effective Mortar Area (mm²) (in²)	% of V-Tie™ Pull-Out Capacity
V-Tie™	7250 (11.24")	100
Z-Tie	4275 (6.63")	59
Rectangular	4275 (6.63")	59
Triangular	5400 (8.37")	74

AIR LEAKAGE RESULTS

Air leakage tests were conducted in accordance with ASTM E283 "Standard Test Methods for Rate of Air Leakage Through Exterior Windows, Curtain Walls, and Doors." The 2000 mm x 2000 mm (6.6' x 6.6') test specimen assembly was identical to the wall configuration presented in Figure 1, with the exception of the BVTS tie system (22 ga. strip tie with one fastener) being used.

Twenty five 65 mm (2.56”) BVTS (spaced at 600 mm [24"] o.c. vertically and 400 mm [16"] o.c. horizontally) were inserted through the 52 mm (2") rigid insulation, vapour barrier and 12 mm (0.5") gypsum sheathing onto the metal studs and fastened to the metal studs with 4.8 mm (0.19") diameter self-tapping sheet metal screws. The vapour barrier consisted of Perm-A-Barrier (W.R. Grace) and was applied on the exterior face of the gypsum sheathing.

Positive and negative test pressures were placed on the wall specimen. At pressures up to 500 Pa (0.0725 psi), the air leakage was less than the least detectable value of 0.02 l/s/m² (0.025 gal/min/ft²) (as dictated by the monitoring system equipment). At pressures up to 1250 Pa (0.18 psi), the air leakage was less than the detectable value of 0.1 I/s/m² (0.123 gal/min/ft²). The equivalent wind velocity comparable to a 1250 Pa (0.18 psi) pressure is 158 km/h (98 mph). Note that ASTM E283 provides a default test pressure of only 75 Pa (0.01 psi).

RECOMMENDED DESIGN LOAD AND DEFLECTIONS

1.	Free Play (maximum):	0.74 mm (0.029")
2.	0.45 kN (100 lbs) Deflection: - free play not included: - including free play:	0.45 mm (0.018”) 1.19 mm (max) (0.047”)
3.	Recommended Design Load:	0.67 kN (150 lbs)
4.	Recommended Design Load Deflection - free play not included:	0.76 mm (0.03”)
5.	Maximum Recommended Spacing:	Horizontal	Vertical
		400 mm (16")	600mm (24")