Wednesday, May 27, 2009

Porch/Deck tie-down applications

Recently we were asked to provide hurricane tie-downs for uplift protection for a customer's deck as shown above. There is no place to sit our top plate, like the 2x4 top plate in stud wall construction. Our engineers offered two solutions.

1. Photo one shows that you can drill a 3/8" hole upwards between the two 2x12s and then drill a 1" wide by 4" deep hole for the cable vise to sit. This meets the IBC codes and maintains out hold-down values. But before you drill through a support beam check with your local codes to make sure there's no variance in codes.

2. A easier and better solution is to use a cable bale and yoke to hold the cable vise in place, as seen in photo two. It is a simple, easy, and quick method to wrap the support rafter and hang the vise. The cable is extra high strength, so you will not lose any hold-down value. If you have a shorter or smaller span, you may have only one 2 x 12 or 2 x 10 so you will need the cable bale.