The heel joint of a trussed rafter is the most critical part of the rafter under standard conditions. The lumber that used to be used for the trussed rafter was 1 5/8” x 3 5/8”, recently this was changed to 1 ½” x 3 1/2”. This has caused for improvements in the design of the heel.
The improvements in the heel joint have more than exceeded the requirements to compensate for the smaller lumber sizes. Because of these heel joint improvements it was unnecessary for the trussed rafters to have to be redesigned.
Reinforcing the Heel Joint
By adding a few features a heel joint can be greatly improved. If you add a short vertical 2 by 4 strut it is the same as a short wedge between the upper and lower chords. Both of these can equal what a nailed heel joint with lumber gusset plates can do in terms of strengthening the heel joint. With the heel joint being the most important part of a trussed rafter it’s important to understand how to improve the heel.