Introduction: Before you dig postholes, check with your local building

department for specific code requirements for the type, depth, and strength

of deck posts and footings. These codes are based on local climate and terrain

Footings must be stable in soft soil, withstand frost heave, and provide a base

to keep posts or beams above decay-causing moisture.

The depth for post footings should be below the frostline

(the depth to which frost permeates the soil) to prevent movement

caused by freezing and thawing. This depth varies with local climate.

You may be required to place a precast pier pad on gravel below the frostline.

A posthole normally is between 24 and 42 inches deep, depending upon the

soil type, the depth to the frostline, and the height of the post. If the soil at

the base of the hole seems loose, compact it with a tamper. Don’t try to dig

postholes with a shovel; at the least you should borrow, rent, or buy a posthole digger.

If your design requires a large number of holes, rent a power auger

(see Using Specialized Tools, Related Projects) or hire a contractor to

handle the job. If you rent a power auger, be sure to get thorough instructions on its use.

	1 Set a fiber-form tube into each hole and fasten 2x4 braces to the sides with decking screws. Center the tube under the mason’s line and check for plumb. Drive short cleats into the ground and attach them to the braces. Cut a piece of rebar to length and place it in each tube. Fill each tube with a foot of concrete. After a few minutes, lift the rebar 4 inches off the bottom.

	2. Pour the footings
		Fill the remainder of the tube with concrete. Before the concrete sets, insert an anchor bolt into the center of the footing. Leave the threaded end protruding upward with the shank perpendicular to the footing surface. Smooth the surface of the concrete. After the concrete is set, the post anchor can be positioned on the bolt.