How to Build a DIY Backyard Fence: Part 1
"Dunn DIY welcomes Trish Mahoney, Seattle DIYer and the brains behind the popular lifestyle blog, Modern Thrifter! Here, Trish shares the first part of a two-part series on a beautiful backyard fence project."
Materials
Dunn DIY welcomes Trish Mahoney, Seattle DIYer and the brains behind the popular lifestyle blog, Modern Thrifter! Here, Trish shares the first part of a two-part series on a beautiful backyard fence project. For the rest of this project, be sure to check out How to Build a DIY Backyard Fence: Part 2. Take it away, Trish!
When we bought our house, we knew the fence would need to be replaced. Most sections of it were 30 years old, rotten, covered in ivy—and those were the nice sections. The bad sections had boards falling off, or the section was missing entirely.
We live on a busy street so having a fence makes a huge difference for the privacy we have in our home. We had a few bids from contractors, because at first, the idea of building it ourselves was a little overwhelming—both because of the time commitment and also because our house is on a steep slope with tons of trees on the property line.
After seeing the bids come in way over our price range, we mustered the courage to start planning a fence DIY. We knew we wanted to do a fence with horizontal slats, and because of the style of our midcentury modern house, we decided to stain the fence black.
We decided to break up the project into a few different weekends, and our first step was to gather tools and supplies.
Step 1: Call 811
Call 811. This is an important step before starting any construction project that requires digging. We called on a Wednesday and planned to start digging on the following Saturday. By Friday all five utility companies had come out and marked the pipes/lines. I suggest giving yourself a bit more time, just in case they can’t get it done that quickly. This service is free, and is really important.
Note: Generally the folks that come to your home mark the location of underground wiring, pipes, etc. with spray paint. If you have areas - artificial turf would be one example - where spray paint would ruin things then post a sign asking that no permanent mark be left on those surfaces.
It’s also a good idea to check with your city’s code/permit department. Our city doesn’t require permits for fences 6’ or less, but there are some regulations on distance from the road that are important to be aware of.
Step 2: Mark your fence line
Our first step after demolishing the old fence was to mark our new fence line. We pounded a stake into the ground at each end and strung a string tightly between the stakes.
Step 3: Mark your post locations
We wanted our posts to be spaced roughly 6’ apart (adjusting slightly at each end to accommodate the overall length of the fence). We measured and marked each post location by pounding a in a wood stake along the string fence line.
Step 4: Dig your post holes
We planned to sink the posts 3’ deep for our 6’ fence. This depth can vary depending on the height of your fence and the amount of wind your fence will have to stand up against, but generally, it’s best to sink them between 1/4 and 1/3 as deep as the above ground finished height.
We started by loosening the ground with the san angelo bar, and then dug the hole wider and deeper using a manual post hole digger. The finished hole should be around 10” wide. This worked great for the first hole, but then we ran into some really hard soil on the next hole. We were pressed for time, and really needed to get the posts all set in one day, so we made the decision to rent a gas-powered auger. It was a great choice. It saved us hours and hours of work for less than $75.
Step 5: Plumb your posts
This can be done at the same time as you pour the concrete, but we chose to level and plumb (line up vertically) the posts first and secure them with stakes before we poured the concrete. We used a 4’ level and secured the post, once it was in position, with two stakes and double-headed nails (for easier removal). We didn’t worry about the height of the posts (they were all above the 6’ mark), and they will be cut down to the right height later.
Step 6: Pour your concrete
There are a few different ways to do this. The cement can be premixed according to the directions on the bag, or you can mix it directly in the ground, which is what we chose to do. To mix it in the ground, fill the hole 1/3 full of water and then simply empty one bag into the hole—mixing it evenly. If you use this method, make sure you don’t add too much water, or you will wash out too much of the cement mix.
Step 7: Remove your stakes
There is probably the perfect time to remove the stakes—after 30 minutes when the concrete has started to set. We missed that window. Rookie mistake, I guess. After we pulled out the nails, we just used the sledge hammer to break them off at ground-level.
Step 8: Stain your posts
This step isn’t necessary, as the wood is pressure-treated, but we wanted our fence to look modern and bold, and I don’t particularly care for the look of wood as it ages, so we chose to stain the wood. Ideally, we would have done this to all of the posts before we set them in the ground, but we ran out of time before we needed to start the construction.
We chose to use a solid-color outdoor stain and had it tinted to the color we picked out. We also decided to brush the stain on as opposed to rolling it, because it’s easier to get into the cracks and incised areas of the wood with the brush. It also takes forever. and ever. In the end, though, it’s totally worth it.
Note from Kirsten: This problem can be easily solved by purchasing non-incised pressure treated posts. 
