There are two methods to fixing our carports to the ground, method one is to bolt each post to a concrete foundation that is suitable and sufficient for the size of the carport you are installing. These are normally a size of 600mm x 600mm x 600mm. Method two is to make a hole varying in size up to 600mm x 600mm x 600mm, once the roof sheets and carport have been installed, backfill concrete around the post (cast in) then make good around the post.