Questions Answered: CSHP High-Performance Coiled Strap

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Issue #11244 - November 2019 | Page #108
By Rachel Holland

We recently hosted an interactive webinar in which our new high-performance coiled strap’s product manager, Thom Murphy, and I discussed how an innovative embossment is a game changer for coiled strap, making it easier and faster to install with a standard framing nailer. During the one-hour webinar, we reviewed the benefits of a continuous load path as well as key uses for coiled straps. We also related what was involved in the design and testing of the embossment. If you missed the conversation, you can still watch the on-demand webinar and earn PDH and CEU credits here.

During this live webinar, which was held in February, we had a lively question-and-answer session with attendees. Here is a curated selection of Q&A from that session. You can find the complete Q&A here.

Installation

  1. Do off-center nails reduce the rated value of the straps?

    We do not have a load for off-center nails currently as they have not been tested in connectors.
  2. How does the strap affect the nailing of the sheathing?

    Typically sheathing is installed first, and then the strap is installed over it. In this case, the CSHP doesn’t interfere with the sheathing installation any more than a flat strap would.
  3. Where can we find out whether a 1 1/2” nail can be used if the strap is applied directly to framing?

    Page 260 of the 2019 Wood Construction Connectors catalog (C-C-2019) has nail substitutions which apply a 1.00 adjustment factor allowing 0.131” x 1 1/2” and 0.148” x 1 1/2” nails to be used instead of 2 1/2” nails of the same diameter. If installing the strap over plywood, however, one needs to use a 2 1/2”-long nail, minimum. (See footnote 3.)
  4. What capacity reduction would you have if a contractor happened to install the strap backwards (with “this side up” facing down instead of up)?

    Please see this engineering letter for information on how to compensate for reduced loads when the strap is installed backward.
  5. If the nail gun misses the center, will that compromise the strap integrity?

    Yes, it could, just as it can with other coiled straps.
  6. Can I use screws with this strap?

    At this time, the CSHP straps are not load rated for screws.

Testing and Approval

  1. Does this product have an ICC certification?

    CSHP is listed in ICC-ES ESR-2105.
  2. When specifying fewer nails than are needed to achieve the maximum load, is there a minimum number of nails allowable (for instance, when developing a strap a long distance into a diaphragm)?

    You can use a reduced number of nails. Reduce the allowable load per the calculation in footnote 4 on page 266 of C-C-2019.

Strap Thickness

  1. What is the overall thickness of CSHP18? Any issues with the finish of the install?

    Compared to installation using a flat 18-gauge strap, the nail sticks up 0.005” higher in the CSHP. There are always tolerances as well, so the difference can sometimes be greater or smaller than that.

Web App & Literature

  1. What’s the reason for switching from 10d, 16d and similar “penny size” designations in the tables?

    The reason is that there was confusion in the field about what a 10d or 16d nail diameter is (e.g., are we referring to a box nail, a common nail or a sinker nail?). Feedback from the field was that listing the actual inch diameter by the inch length was easier to understand for most contractors.

 

The article, Questions Answered: CSHP High-Performance Coiled Strap, 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.

Copyright © 2019 Simpson Strong-Tie Company Inc. All Rights Reserved

You're reading an article from the November 2019 issue.

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