I have just moved into a new home and during the construction I noticed that one of the trusses in the garage was damaged. The web plate had come off in two different locations. I notified the builder and they said they would take care of it. Approximately two weeks after I moved in, I noticed the ceiling in the garage started to sag, so I went into the space above the garage and found the truss was never repaired. I again notified the builder and they sent someone to fix it. I went and looked at the fix and this is where my question comes in. Their fix was to take 4 pieces of plywood (I'm not sure if it was 1/2 or 3/4 in.) approximately 18 in. square and nail them on either side of the joints where the webbing was. Is this a correct type of fix for a truss joint? If not, can you recommend the correct way to fix them?
The type of plywood gusset fix that you are describing is a common repair on trusses. To determine if it is the proper repair on your trusses, you will need to obtain the repair detail drawings that most likely came from the truss manufacturer. When you notified the builder of the damaged trusses in your garage, the builder should have notified the truss manufacturer immediately so that the manufacturer's engineer could prepare the repair drawings. Without proper repair detail drawings, repairs should not be attempted.