Flagpole Foundation Dimensions
Ground Set or Shoe Base
Ground Set
Ground Set installations are the most robust and widely used flagpole mounting method. This installation involves burying the flagpole shaft in a concrete foundation, with the depth of the burial equal to 10% of the flagpole's mounting height.
NAAMM's Metal Flagpole Manual offers basic suggestions on foundation measurements in firm, dry soil only using dry tamped sand and 3000 PSI concrete. Soil conditions vary by site. Exact foundation requirements should be verified by a Structural Engineer with knowledge of soil conditions in your locality.
Foundation Dimensions
| Flagpole Height |
A | B | C | D |
|---|---|---|---|---|
| 20'-0" | 2'-0" | 2'-6" | 30" | 24" |
| 25'-0" | 2'-6" | 3'-0" | 36" | 24" |
| 30'-0" | 3'-0" | 3'-6" | 36" | 24" |
| 35'-0" | 3'-6" | 4'-0" | 36" | 30" |
| 40'-0" | 4'-0" | 4'-6" | 45" | 36" |
| 45'-0" | 4'-6" | 5'-0" | 45" | 36" |
| 50'-0" | 5'-0" | 5'-6" | 50" | 42" |
| 60'-0" | 6'-0" | 6'-6" | 60" | 48" |
| 70'-0" | 7'-0" | 7'-6" | 60" | 48" |
| 80'-0" | 8'-0" | 8'-6" | 72" | 48" |
Shoe Base
Shoe Base installations are typically used when an above ground installation is required.
All 20' to 80' flagpoles with a 4"+ butt diameter can be provided in a shoe base installation option.
Foundation Dimensions
| Flagpole Butt Dia. |
AA Base Square | BB Base Height | CC Bolt Projection | Bolt Diameter | Bolt Circle Diameter |
|---|---|---|---|---|---|
| 4" | 7-1/2" | 3" | 2" | 3/4" | 6-1/2" - 8" |
| 5" | 7-1/2" | 3" | 2" | 3/4" | 7-1/2" - 8" |
| 6" | 9-3/4" | 3-1/2" | 2-3/4" | 1" | 9" - 10" |
| 7" | 10-1/2" | 3-11/16" | 2-3/4" | 1" | 10" - 11" |
| 8" | 11-1/4" | 3-15/16" | 2-3/4" | 1" | 11" - 12" |
| 10" (Up to .250" Wall) | 14" | 4-7/8" | 3-1/4" | 1" | 14" - 15" |
| 10" (.312" Wall & Larger) | 14" | 4-7/8" | 3-1/4" | 1-1/4" | 14" - 15" |
| 12" | 7-1/2" | 3" | 2" | 3/4" | 16" - 18" |