While many hurricane ties have been evaluated with 8d x 1½” nails for compatibility with nominal 2x roof framing, some require the use of a longer, 8d common (2½” long) nail and others require a larger-diameter 10d nail. It’s also essential to pay close attention to the diameter and length of the fasteners specified in the Simpson Strong-Tie literature. H2.5T Installed on 2×4 Truss Bottom Chord Fasteners with Hurricane Ties H2.5A Installed on 2×4 Truss Bottom Chord Figure 8. In this case the ideal choice would be the H2.5T, which has been specifically designed for a 2×4 truss bottom chord. This is actually such a common mis-installation that we specifically tested this scenario and have developed an engineering letter on it (note the greatly reduced capacity).

For example, an H2.5A would not be compatible with a roof truss configured with only a nominal 2×4 bottom chord over the plate since the two upper nail holes in the H2.5A will miss the 2×4 bottom chord (see Figure 7). H2.5A and H1 Hurricane TiesĪdditionally, the height of the hurricane tie and the wood members being attached should be compatible.

For example, use our new H1.81Z (not the H1Z) for 1¾” wide engineered roof framing members.įigure 5. While the majority of the hurricane ties that Simpson Strong-Tie offers are one-sided (such as the H2.5A), some are designed so the truss or rafter fits inside a “U” shape design to allow for fastening from both sides (such as the H1). If using the latter, make sure the width of the truss or rafter is suitable for the width of the opening in the hurricane tie. Proper Placement of (4) H2.5A’s to Avoid Fastener Interference Allowable Load Comparison for Single and Multiple H2.5A Connectors Figure 4. Check out the recently updated F-C-HWRCAG16 High Wind-Resistant Construction Application Guide for allowable loads using multiple connectors and for guidance on the proper placement of connectors so as to avoid potential overlap or fastener interference. What if the tabulated loads in the catalog for a single connector just aren’t enough? Use multiple connectors! An important note on using multiple connectors, though: Using four hurricane ties doesn’t always mean you’ll get 4x the load. Alternate seismic and hurricane tie applications. Traditional Linear Interaction Equation Figure 2. I won’t go into too much detail on this topic since it was covered in a recent blog post, but in lieu of the traditional unity equation shown in Figure 1, certain Simpson Strong-Tie connectors (hurricane ties included) are permitted to use the alternative approach outlined in Figure 2. When the connector is resisting lateral loads, its capacity to resist uplift is reduced. It’s also important to consider combined loading if you plan to use the tie to resist both uplift and lateral loads. at each end, don’t select a hurricane tie with a published capacity of less than 600 lb.

If your building’s roof trusses have an uplift of 600 lb. In this post, we’ll outline some of the key elements to consider when selecting a hurricane tie for your project. This assortment of models raises the question, “How do you select the right one?” Simpson Strong-Tie manufactures approximately 20 different models of hurricane ties, not counting twist straps, other clips, or the new fully-threaded SDWC screws often used in the same applications. They are most commonly used to resist uplift forces, but depending on regional design and construction practices, hurricane ties may also resist lateral loads that act in- or out-of-plane in relation to the wall. They play a critical role in a structure’s continuous load path and may be used in a variety of applications, like attaching roof framing members to the supporting wall top plate(s), or tying wall top or bottom plates to the studs. When it comes to wood-frame construction, hurricane ties are among the most commonly specified connectors.

Simpson strong tie roof rafter