With the recent introduction of our new LSSR rafter hangers for 2x lumber, we thought we’d provide some background on how these new hangers were developed and why.
Field-adjustable sloped and skewed hangers allow designers to specify widely available, economical connection solutions. They were first developed to improve on traditional sloped and skewed hangers that had to be special-ordered or custom manufactured. While special-order hangers are still sometimes necessary, having off-the-shelf, field-adjustable joist hangers gives designers an attractive alternative for many common conditions.
The discontinued LSSU joist hanger series, which the LSSR replaces, needed to be installed before the joists were in place. We heard from installers that it would be helpful for job sequencing if the hangers could be installed after the joists or rafters were tacked into place. This feedback led us to design our LSSR and LSSJ hangers, both of which are easy to adjust in the field and can be installed after joists or rafters are in place.
Building designs often require connections for supported members that are at a skewed and sloped angle rather than perpendicular to the header. Several of our other hanger series are adjustable for skew only or slope only, but not for both. For example, our THASR/L series is designed to accommodate connections skewed from 22 1/2° to 75°. Conversely, the LRUZ ridge hanger is designed to support rafters at ridge beams with roof slopes of 0:12 to 14:12. Finally, our SUR/SUL/HSUR/HSUL series is not adjustable, but the models are manufactured with a fixed right or left skew of 45° in sizes to accommodate several joist sizes. The LSU/LSSU and LSSJ series field-adjustable hangers were developed to offer our customers off-the-shelf accessibility and convenience so they wouldn’t have to custom-order skewed and sloped hangers. Even so, the LSU/LSSU product design still required that the hanger be attached to the carrying member before installation of the carried rafter/joist. This required a disruption of the normal installation sequence in the field. We felt the need to innovate and offer our customers more flexibility to ease installation during construction.
In 2018, Simpson Strong-Tie released the patented LSSR hanger series. This new series of hangers offers customers the ability to install the hanger after the framer has temporarily attached the rafters into place. Hence, the “R” in LSSR stands for “retrofittable.” To start with, we offered lighter-gauge LSSR sizes for engineered wood products (EWP) such as 1 3/4”-wide LVLs, along with the most common I-joist widths. We offer the heavier-gauge sizes of LSSR hangers for the more common larger solid sawn lumbers sizes such as the double 2x and 4x. The LSSR hangers also allow the installer to have the flexibility to make either miter or straight cuts to the ends of the rafters. Additionally, we improved the LSSR’s adjustable hinge with our new reinforced hinge feature. The LSSR hangers are shipped in the non-skewed and non-sloped orientation, and customers can adjust the slope and skew as needed to meet field conditions. A detailed installation video is posted on our website for customers to watch at their convenience on their phones and mobile devices. Click here for more details.
Customers will also be happy to know they may replace nails with our proprietary Strong-Drive® (SD) Connector screws for higher allowable loads, as we illustrate in an engineering letter on our website.
With the success of the initial LSSR models, we moved on to develop additional models in this series for single 2x solid sawn member applications. We wanted to improve and innovate by combining the versatility of the LSSJ with the robustness of the LSU/LSSU. In the fall of 2021, we proudly introduced our LSSR26Z, LSSR28Z, and LSSR210Z.
As the names suggest, these new LSSR models are designed to support 2×6, 2×8, and 2×10 solid sawn lumber sizes, respectively. These models replace the LSU26, LSSU28, and LSSU210. The new LSSR models allow the installer to use 2x solid sawn lumber with straight-cut ends for plated truss and other applications without the need to specify left or right versions. The LSSJ hangers will remain our economical and light-duty hangers for 2x sawn lumber. The allowable loads for both the LSSR and LSSJ hangers are posted on our website and in the new 2021 Wood Construction Connectors catalog (C-C-2021).
Installation is similar to earlier LSSR models. The flange design allows for easy skew adjustments from 0 to 45° left or right. The swivel seat with the patented reinforced hinge adjusts the slope easily from 0 to 45° up or down. All LSSR models are offered with our ZMAX® coating for medium corrosion resistance in indoor and limited outdoor use. These new models can be used on miter- or straight-cut rafters and joists. All LSSR models are currently in the ER-280 code report.
Stay tuned, because we’ll soon be offering fastener substitutions with these 2x models using our Strong-Drive® (SD) Connector screws for higher allowable loads. For these and other updates, check back on strongtie.com soon.
The article, Field-Adjustable Sloped and Skewed Hangers — Introducing New LSSR Sizes, appeared first on Simpson Strong-Tie Structural Engineering Blog. To sign-up to receive the Engineering Blog in your inbox, go to seblog.strongtie.com/subscribe.
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