How Would You Have Done This Truss Repair?

Originally published by the following source: SBC MagazineJune 17, 2019
by Evan Protexter, EIT

   

A great benefit to trusses is that, even when damaged by plumbers or water leaks, they can be repaired to perform as originally intended. Since trusses are engineered, they have a benefit over other structural members in that they offer greater flexibility when it comes to repair options.

In the case of this article in the Journal of Light Construction, three floor trusses were exposed to water due to a leak in the roof. Since replacing the trusses was cost prohibitive, the rehab company called in an engineering company to design a repair for the trusses, allowing the floor system to stay intact. These trusses had trimable I-joist ends, allowing for additional bearing location flexibility. The engineering company opted to add additional bearing support at the original bearing location, and design a repair to strengthen the supporting members.

Step 1:

The repair specified that 2x4 blocks be inserted between the top and bottom chords at the bearing location. These “squash blocks” are intended to stiffen the truss at the bearing location and prevent damage to the truss.

Step 2:

3/4” plywood was used as a gussets extending 3’ from the end of each truss. These gussets were marked to show the truss outline and 3” nails were used to fasten the gussets to each side of the truss.

Step 3:

Trusses were then lifted, the rotted pieces of the trusses were cut away and a new low-profile bearing plate was put in place, which allowed the room to be finished at a later date.

For situations like this, where a repair was necessary, SBCA has assembled a research report and educational program to provide best practice guidance to the market. These documents outline common situations that may come up during a repair. Another reference at component manufacturer’s disposal when it comes to truss repair is Building Component Safety Information B-5, which provides standard guidance for truss repairs. These documents, along with many other helpful sources of information related to truss repairs and modifications, can be found in SBCA’s Topical Library.

The repair specified by the engineer in this case is an effective solution, but given our readers’ expertise regarding floor trusses, how would you have approached this repair? Do you see an opportunity for a more cost-effective repair solution? Let us know what you think by joining the discussion on Facebook, or by submitting your comments to editor@sbcmag.com.