Concrete – Adding rebar to deck footings and piers


I've heard a few people mention adding rebar to deck footings and piers to make them stronger, but I haven't been able to find any details on how exactly to do this.

Is it sufficient to just hammer 3 or 4 pieces of rebar into the bottom of my hole so they stick straight up and then pour the concrete over them? If not – what is the proper way to do this?

Best Answer

Concrete does not have very good tensile strength. Rebar is laid in such a manner that it adds tensile strength in the concrete.

Depending on the size and weight load the pier/footer assembly is expected to support and the length of the pier, it could be reinforced in the following manner.

  1. A rebar circle in the footer to prevent weight spread from cracking it
  2. Vertical members in the pier with L bent ends that sit over the top of the circle bent piece in the footer to reinforce against bending forces in the column

For a bridge just built here, they spiral-wrapped the vertical rebar reinforcement with a long helical bent reinforcement as a seismic forces precaution to prevent the rebar from shedding the concrete (rebar doesn't have very good strength against compression and bending).