Do I need rebar inside my post?

In most situations, you do not need rebar for a Trex post footer. A post footer is a small monolithic pour that fills up a post hole. Adding rebar isn't usually needed for these type of footers. In a rare case, you may want to put concrete or grout inside the cavity of the post (perhaps to make the base more rigid, for example). If so, rebar can help to stabilize the internal concrete so it does not crack inside the post. Here is an example of how rebar could be used inside the post. Please note, it is not recommended that concrete extend very far up the post outside of the ground. Concrete can swell and could potentially split the post. While there are no specification recommendations, you would typically want to limit the concrete to no more than 1/3 of the post height. Using concrete inside of a post could void the warranty.