Steps // How to Install an In-Ground Flagpole
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How to Install an In-Ground Flagpole Overview

 
Step One // How to Install an In-Ground Flagpole

How to Install an In-Ground Flagpole Overview

toh master carpenter Norm Abram raising a flag on the installed in-ground flagpole
Photo by David Albanese

To install a flagpole, the first step is deciding where in the yard to put it. You can do this by assembling a mock-up with PVC pipe and couplers. One person should hold up the pole in various spots so a second person can judge the effect from afar. A grassy spot in a prominent place by the front door of the house is ideal.

To choose a pole's height, consider the height of the house or building: 18 to 25 feet for single story building, 25 to 30 feet for two stories, and 30 to 40 feet for three stories.

For this project, This Old House master carpenter Norm Abram installed a pole with a linchpin assembly, which allows the pole to be lowered easily for painting or major storms.

 
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Dig a Foundation for the Anchor

 
Step Two // How to Install an In-Ground Flagpole

Dig a Foundation for the Anchor

dig a foundation for the anchor to install an in-ground flagpole
Photo by David Albanese

The day before installation, dig a foundation hole 30 inches deep and 24 inches in diameter, using a post-hole digger and shovel. This will hold the painted steel anchor, which supports the pole and prevents ground moisture from wicking up and rotting the wood. For soil that doesn't drain well, add 6 inches of gravel or crushed rock before pouring the concrete. The base should be high enough that the pole can swing up and down with ease. Shovel in 6 inches of concrete, let it set for a few minutes, and drop in the anchor. Check the anchor's alignment using an 18-inch bubble level, then fill the hole with concrete and trowel it smooth.

 
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Drill Holes for the Pivot Bolt

 
Step Three // How to Install an In-Ground Flagpole

Drill Holes for the Pivot Bolt

drill holes for the pivot bolt to install an in-ground flagpole
Photo by David Albanese

After the concrete has set for 24 hours, rest the pole on two padded sawhorses. In order to center the cleat on the pole's halyard side, measure 42 inches from the bottom. Using an 11/16-inch bit, drill holes for two ⅝-inch bolts..

 
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Attach the Finial

 
Step Four // How to Install an In-Ground Flagpole

Attach the Finial

attach the finial to install an in-ground flagpole
Photo by David Albanese

To affix the truck (the flanged top that holds the finial and through which the halyards are threaded), set the double sheave into a notch on the top of the pole, so a sheave with the halyard pulled through lines up with a cleat on the base. Before screwing on the truck, coat the inside and edges with silicone caulking for a watertight seal. Fit the finial into a ½-inch threaded hole in the center of the truck.

 
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Install the Pole

 
Step Five // How to Install an In-Ground Flagpole

Install the Pole

install the pole to complete an in-ground flagpole
Photo by David Albanese

Set the pole into the anchor and insert the pivot bolt. Adjust the pole until it is plumb, checking how it looks from afar as a helper holds it steady. Holding the preferred position, mark the pole at the predrilled holes on the anchor. Remove the pole, rest it on the padded sawhorses, and drill holes for the locking bolt.

Insert the pole into the anchor again and install the pivot bolt. Finally, install the locking bolt and finger tighten it. Once again, check to make sure the pole is plumb.

 

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