How Deep to Dig Fence Post Holes

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Fences are fantastic for fixing up a boring yard, creating a private space from peering neighbors or keeping animals in — or out — of your favorite spaces. A good fence can last for decades, and building a sturdy, durable fence starts at the foundation. Erecting a solid fence is a fairly fast project once the foundation is firmly in place.

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What Makes a Good Hole

Digging a hole seems like the easiest part of the process. Even a kid can get a good-sized hole going in a small amount of time. But the hole is a pretty important part. Too big, and you can jeopardize the structure's ability to hold up to strong winds. A hole that is too small is simply an annoyance as you have to drag everything out and start digging all over again.

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The post holes you dig for your fence need to be evenly spaced from top to bottom. When you begin to dig a hole with a shovel, it tends to be larger on top where the shovel uses the ground for leverage to scoop out the earth. The V-shaped holes that come from digging with a shovel increase the chances of the posts heaving with frost.

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One way to avoid this is by using a posthole digger, which creates straight sides. You can get manual post hole diggers and powered post hole diggers to make the job easier.

Using a Post Hole Digger

Start by marking the fence line and the centers of the post holes. Standing over the hole, push the post hole digger handles together, opening the blades. Drop the digger into the ground, using the center mark as a guide. Spread the handles, which closes the blades, so you can remove soil out of the hole. Repeat this process until you create a hole of the correct size.

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Powered post hole diggers use an auger to dig the hole for you. Some types require two people to control the auger. Center it over the post hole spot and start digging. You don't need to push hard on the auger as the weight of it does most of the work. When you've reached the right depth, shut off the auger and pull it out of the hole to drag the dirt out with it.

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Hole Depth Considerations

A beautiful fence starts with a well-made hole. To dig a good post hole, you need to go down a third of the height of the post height above ground. If your post is 6-feet tall, you will dig down at least 2 feet.

For the width, you need to make the hole three times the width of the post you intend to use. You need to dig a 12-inch wide hole for a 4-foot wood post. Gates require a hole with a depth of 36 to 40 inches in the ground and a diameter of at least 12 inches.

Safety and Tips

Before you go around digging post holes on your property, give a buzz to the 811 call center in your state to ensure you won't be knocking out any power, shoveling into sewage or water lines or taking down cable before the big game. Always wear safety goggles when digging as well as a long-sleeved shirt, pants, and work gloves because digging brings up a lot of loose objects that can be sharp and go flying when hit from above.

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