The rebar is used to connect the new footing to the old footing as shown
in the picture above. A hole is drilled into the old footing about 9
inches and then a special concrete epoxy is used to hold the rebar
securely into the old footing.
The horizontal rebar is not yet connected to the dowels that will
provide structural support for the new concrete slab.
This is a common problem when trying to tie in an existing footing to a
new footing used while building a room addition. The new footing
required for the room addition could have a depth of 24 inches while the
old footing from the existing house only has a 12 inch deep footing.
If this problem occurs you can contact your engineer for further
instructions. Most of the time the engineer will instruct you to drill
the holes for the new rebar dowels at least 2 inches from the bottom of
the existing footing and then proceed to connect the dowel to the
horizontal rebar in the new footing.
