Truss Plate Problems

I have attached free graphics showing truss plate issues.


Nice… Thanks for those.

Great graphics, Randy!

Thanks from all the InterNACHI inspectors! :smile:

Nice work Randy! Thank you!

Nice Randy! Thanks!

Here is a narrative with some references for gap between the truss and the gusset plate…

There was metal connector plate(s), commonly referred to as gusset plate(s) observed which had a gap of greater than 1/32" between the gusset plate(s) and the truss member(s). Gaps greater than 1/32" (.031"-.793 mm) at gusset plates significantly reduce the structural integrity of the metal connector plates. According to the Structural Building Component Association (SBCA) gusset plates with a gap from 1/32" to 1/16" can have as little as 60% effectiveness, gaps from 1/16" (.062"-1.587 mm) to 3/32" (.093"-2.381 mm) as little as 40% effectiveness, gaps larger than 3/32" (.093"-2.381 mm) have zero effectiveness. We recommend that a licensed professional engineer evaluate and prescribe any needed repairs which should be performed by a qualified licensed professional contractor. The repair documents produced by the engineer should be filed with the local building authority and a copy of the documents should be given to the home owner for their records.

Reference Truss Plate Institute and ANSI/TPI 1-1995 Tooth embedment gap is defined as the distance between the underside of embedded metal connector plate and the surface of the wood member. Tooth embedment gap shall be measured through the slot opening of the metal connector plate. The number of effective teeth per each metal connector plate contact area shall be determined based on the effectiveness ratios shown in Table

And I’d like to add a friendly reminder to this thread:

  1. machine-applied nail plates can’t simply be hammered back into position in the field, once they pull out or are damaged by fire
  2. retrofit/repair plywood gussets and nailing schemes have to be sized.

Also, while I’m mentioning fire, charred wood can be checked by an engineer for determining whether the wood can stay or has to be replaced.

1 Like