Setting your posts correctly in a straight line when building a fence is the most important part of the project.
They must be set plumb and level so that the fence will have a professional, cohesive appearance when the job is complete.
I’ve seen many pressure-treated wood fences installed according to common practices; however, the posts were too saturated with chemicals they use to make them resist decay.
When they finally dried after a year or so, the lumber developed bends and curves in it making the fence appear wavy looking. You don’t want that.
See also: Designing A Gate For A Fence
To get started, decide what kind of concrete you’ll use. There are several different products on the market; I suggest you try fast-setting concrete. I use it on all fence jobs. You’ll need about 1 to 1 ½ bags of Kwikset concrete for each post you set.
The tools you will need are:
- Post hole digger. If a lot of post need to be dug, you will need to rent a 1 or 2 person auger at the local supply shop. Even then it’s back breaking work.
- Mason Line. You need to keep your posts in a completely straight line. A straight line equals a straight fence.
- Concrete. I recommend fast-set bags. You just add water after you pour the dry mix in the holes.
- A Carpenter’s Level. Try a 4 foot level and a 2 foot one.
- Stakes. 2 foot and 4 foot for your mason’s line.
- Small Sledgehammer. About the same handle size as regular hammer to pound the stakes into the ground.
- 4×4 Posts, 8-10 feet long. Either pressure-treated or cedar will do. Just be selective in picking p.t. lumber that is on the dry side.
- Crushed Gravel. For drainage at the bottom of the holes.
Installation Procedure. Locate and place stakes on fence outline measurements. Hammer stakes about 1/3 their length into the ground. Attach mason’s line to measured fence corner post locations. Dig your corners first. Dig 24 inches to 30 inches deep for 8 foot wooden post holes. The hole width should be at least double the size of the thickness of the post; about 8 inches.
After digging holes, throw about 2 inches of crushed gravel into the holes for drainage.
Insert a post into the hole. Then, fill holes with the dry concrete mix. Fill the holes up all the way to the top, leaving 4 inches. Take your level and check the levelness of the post on 2 flat sides of the post.
Make sure the posts you inserted into the holes are level. Finally, add water to this dry mix. Check for levelness again.
Cover the surrounding cement with dirt excavated from the holes. Tamp with a garden rake and slope this dirt away from the post.
Next, repeat the steps above for line posts (posts in between the corner posts), closely following your mason’s line you strung from each corner post. Continue on until you finish.
Make sure you wear gardener’s leather gloves when digging with a post hole digger; or else you will have blisters!