How To Make A Fence

The Actual Process

I spent three weekends building a 40-foot cedar picket fence last spring. What follows is what actually happened, stripped of the optimism most DIY guides carry. The basic sequence is simple enough: mark post locations, dig holes, set posts in concrete, attach rails, then mount the boards. Where people get stuck is in the details that never show up on a Pinterest board. Start by running a string line between two corner stakes at the desired height. That line is your only truth for the entire project. Every post, every rail, every board goes to it. If you eyeball it, you will end up with a fence that looks like it got hit by a small earthquake. Use a laser level if you have access to one, but a good old-fashioned line level works fine too. Just don't skip it.

How To Make A Fence Without Wasting a Day

The biggest time sink on any fence project is figuring out where the posts go. A standard 6-foot privacy fence uses posts spaced 6 feet apart on center, which means each section needs two posts and one 6-foot rail board (actually closer to 5 feet 9 inches of clear span once you account for the post width). If you are running 40 feet total, you are looking at roughly 7 to 8 posts depending on whether the span hits exactly or you need an intermediate support. Dig the holes to a depth of about 24 inches for a 6-foot fence in most soil types. That's the rule of thumb: one-third of the above-ground height buried. If you are in clay or heavy soil, that goes deeper. I had one spot in my yard where the hole hit groundwater at 18 inches and the concrete would not set properly because the water was displacing the mix. What I ended up doing was driving a gravel base down to solid dirt, setting the post in a perforated drain sleeve, and packing the top with coarse aggregate instead of wet concrete. The post is still solid three years later. It just drains instead of sitting in a puddle of mud inside a concrete tube. Use a manual auger for the first few holes to get a feel for the soil. Once you know what you are dealing with, renting a gasoline-powered post hole digger saves hours. Renting one costs about $40 to $60 a day and cuts dig time per hole from 20 minutes down to roughly 90 seconds. I would rather spend that $60 than do eight holes by hand in July.

When setting posts, plumb them in both directions before the concrete sets. A post that leans two degrees forward will compound over 40 feet and end up noticeably crooked at the far end. I used a quick-set concrete mix and a 5-gallon bucket to mix each batch. For a 10-inch diameter hole at 24 inches deep, that is about four bags of mix per post. Fill the hole halfway with dry mix, set the post, pour water into the hole until it saturates the concrete, and watch it cure. The trick is getting the spacing right while the mix is still workable. Have someone hold the string line while you pour, or mark your spacing on a board beforehand so you are not guessing. Attach the horizontal rails once the concrete has set for at least 24 hours. Two rails on a 6-foot fence is standard. Use 2x4s or pressure-treated 2x6s. Screws are better than nails here because they hold the rail tighter against the post over time. I used 3-inch exterior deck screws, two per connection point. Nails will loosen within a year and the rails will rattle whenever the wind picks up. Mount the boards next. For a classic picket fence, 5/4 x 3.5 inch cedar boards spaced about half an inch apart work well. That gap allows airflow and prevents the boards from cupping when they absorb moisture. Start from one end and measure as you go. If you add up the gap widths and subtract from the total run length, you get the exact number of boards you need. I found it faster to pre-drill every board through the rail with a 1/8-inch bit before driving the screws. It cuts drilling time from about 45 seconds per board to 15 seconds because the bit does not wander on the curved edge.

If you are building a privacy fence with shadow box or board-on-board style, the spacing math changes. Shadow box uses alternating boards on each side of the rails, which means you need roughly twice as many boards but the fence breathes better and looks consistent from both sides. Board-on-board overlaps slightly, which is cheaper in materials but harder to get even because the front row hides any mistakes in the back row and you have to compensate visually. I prefer shadow box. It takes longer to install but the finished result is cleaner and each board gets to expand and contract independently. The one thing most guides leave out is the gate. A 4-foot gate on a 40-foot run is not an afterthought. It is the hardest part of the whole job. Gate posts need to be substantially bigger than the regular posts. I used a 4x6 pressure-treated post for each side of the gate opening and dug those holes to 30 inches deep. The gate sags if the hinge post is underbuilt, and once it sags you spend more time adjusting hinges than you did building the rest of the fence. Hang the gate with heavy-duty T-hinges, not those cheap flip-latch ones you see at big-box stores. Put a diagonal brace inside the gate frame if it is over 3 feet tall. Without it, the frame will rack under its own weight and bind against the post within a few months. Finishing touches matter less than people expect. A coat of penetrating sealant on cedar or redwood will extend the life by a couple of years. Painted pressure-treated lumber needs a primer designed for wet wood because fresh PT still holds moisture. Don't skip that step or the paint will peel in a season. Cap the tops of every post with a metal or plastic cap. Water pooling inside an open post is how posts rot from the inside out, and you will not see it until the board rips free in your hand.