The most common type of flagpole installation is the in-ground galvanized steel foundation sleeve with base plate and ground spike method, which calls for 1 ft. of the flagpole to be encased in the ground sleeve for each 10 ft. of exposed flagpole height. The diameter of the sleeve should be at least 2 in. greater than the outside diameter of the flagpole, with the area between the flagpole and the sleeve filled with dry sand.
