Shopping checklist
Set a fence post in concrete
Half day · Moderate · 9 steps
Materials
| Done | Item | Quantity | SKU | Price |
|---|---|---|---|---|
| 4x4x8 pressure-treated postCheck the tag says ground contact | 1 per post | 448TR | $36.99 | |
| 50 lb fast-setting concrete | 3 to 4 bags per post | Ask | ||
| 2x4x8 stud (braces) | 1 per post | 102 | $6.99 | |
| #9 x 2-1/2 in deck screws | 1 box | 738287553635 | $34.99 | |
| Drainage gravel | About 1/2 bag per post | Ask | ||
| Goatskin leather work glovesFor digging; switch to waterproof gloves for concrete | 1 pair | 753677468139 | $24.99 | |
| Waterproof work glovesRubber or nitrile-coated, for wet concrete | 1 pair | Ask | ||
| Clear safety glasses | 1 pair | 641817001011 | $12.99 | |
| N95 respirators, 2 pack | 1 pack | 616314929922 | $13.99 |
Tools
- Post hole digger or auger
- Digging bar
- Round-point shovel
- Post level
- String line and stakes
- Tape measure
- Drill/driver
- Wheelbarrow (for regular mix)
- Margin trowel
- Hand tamper
Before you start
- Call Arizona 811 (dial 811) at least two full working days before you dig. Buried gas, electric, water, and communication lines are marked for free, and it's required by state law.
- Wet concrete is caustic. Wear waterproof gloves and safety glasses, and wash splashes off skin right away.
- Pouring dry mix into a hole raises silica dust. Pour low and slow, and wear an N95.
- Wear safety glasses when swinging a digging bar into caliche; chips fly.
- Never leave an open post hole unattended where kids or pets can step in it. Cover it with a board.
Prices are current as of printing and may change. Bring this list to the counter, or call (928) 669-9254. If we don't have it, we can order it.
Set a fence post in concrete
Dig, set, and brace a plumb 4x4 post that won't lean. Repeat it down the line and you have the backbone of a fence or gate.
- Time
- Half day
- Difficulty
- Moderate
- Category
- Concrete
- Steps
- 9
Before you start
- Call Arizona 811 (dial 811) at least two full working days before you dig. Buried gas, electric, water, and communication lines are marked for free, and it's required by state law.
- Wet concrete is caustic. Wear waterproof gloves and safety glasses, and wash splashes off skin right away.
- Pouring dry mix into a hole raises silica dust. Pour low and slow, and wear an N95.
- Wear safety glasses when swinging a digging bar into caliche; chips fly.
- Never leave an open post hole unattended where kids or pets can step in it. Cover it with a board.
Step by step
- 1
Call 811 and confirm your line
Call 811 at least two full working days ahead so utilities get marked. Confirm where your property line is and check any HOA or city rules on fence height and setbacks before you dig.
- 2
Lay out the posts
Set the corner and end posts first, then pull a string line between them. Mark the hole centers along the string. Space line posts to fit your panels: measure an actual panel, since an 8 ft panel needs posts 8 ft on center.
- 3
Dig the hole
Make the hole about three times as wide as the post (10 to 12 inches for a 4x4) and deep enough to bury at least a quarter to a third of the post's length plus 6 inches for gravel. For a 6 ft fence on an 8 ft post, that's 2 feet of post in the ground plus 6 inches of gravel, so about 30 inches deep. Caliche is common in Parker; a digging bar breaks it, and filling the hole with water overnight softens it.
- 4
Add a gravel footing
Pour 4 to 6 inches of gravel in the bottom and tamp it. The gravel lets water drain away from the end of the post instead of sitting against it.
- 5
Set, plumb, and brace the post
Stand the post on the gravel. Check plumb on two adjacent faces with a post level and check its height against the string. Screw two diagonal 2x4 braces to the post and to stakes driven in the ground so it can't move.
- 6
Fill with concrete
For fast-setting mix, pour the dry mix into the hole to about 3 to 4 inches below grade, then add water as the bag directs (roughly a gallon per bag) and let it soak in. For regular mix, combine it in a wheelbarrow first, then shovel it in and poke it with a stick to remove air pockets. A 10 in by 30 in hole takes about three 50 lb bags; a 12 in hole takes about four.
- 7
Recheck plumb right away
Fast-setting concrete stiffens in 20 to 40 minutes, so check plumb again immediately after filling and nudge the post if needed. After that, leave it alone.
- 8
Shape the top to shed water
Trowel the top of the concrete so it slopes down and away from the post. Water that pools against a wood post at the ground line is what rots it. Fill the last few inches with soil or gravel if you want it to blend in, keeping the slope.
- 9
Let it cure before loading it
With fast-setting mix, wait at least 4 hours before hanging rails, panels, or a gate. With regular mix, wait 24 to 48 hours. Keep the braces on until then.
Pro tip
Set the two end posts first and let them cure. Then stretch a tight string between them at the top and bottom, and set every line post to the string. Your fence will run dead straight without measuring each one.