How We Dug Post Holes to Build Our Deck

Before our weekly deck update, we have to say: HOLY COW—you all have incredible homes. So many of you sent house-crashing photos for our upcoming trip to Atlanta for the Haven conference, and we wish we could visit every single one of you. We’ve planned to crash as many homes as time allows, and while we’re a little bummed we can’t see everyone, there’s always a chance on a future book tour in the fall. Huge thanks to everyone who offered to let a toddler, a chihuahua, and two curious bloggers poke around.

Back to the deck. I’m proud of this post title—it includes not one but two deck puns about our recent accomplishments: leveling things and digging holes. Continuing from Deck Day #1, Day #2 wasn’t as productive as we’d hoped. It actually took place the day after Day #1, but since the progress didn’t feel post-worthy we worked a bit more before writing another update. By Deck Day #3 we’d finished hanging the second ledger board and dug all the post holes, so here’s a summary of those last few days of work.

You might remember we left off after hanging one ledger board on the brick side of the alley and prepping the siding side for its ledger board.

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The first task on Day #2 was to hang the ledger board on the house. To avoid putting bolts where the joist hangers would go, we marked all hanger locations first. Because the hangers needed to line up with those already marked on the brick side, I drew a small diagram with my measurements so everything would match. Clara added the crayon scribble.

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The ledger was a bit unwieldy—it’s a single 17-foot 2×8 board—but my dad and I managed to get it in place using a couple of pairs of hands and scrap boards for support. We leveled it and screwed it in without too much trouble. Bolting went faster this time because we only needed 6″ lag screws and we were fastening into wood instead of brick.

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Since the ledger went in quicker than expected, we decided to add attaching all the joist hangers to the day’s tasks. Our goal was to dig post holes by day’s end, and at 11 a.m. we thought we could get the hangers done fast. We used a level and a scrap joist to position and hammer in the hangers, installing every third hanger first to use the full length of the level, then filling in the ones between.

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It was straightforward but took more time than anticipated.

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We had our usual cheering section watching from the door—this time, amusingly, not fully clothed except for a blue cloth diaper. My wife stayed clothed and was extremely helpful with photos and planning while wrangling Clara.

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By about 1 p.m., my dad and I had finished the hangers on one side. We were less confident about our schedule and definitely hungry. Instead of continuing with the brick side, we ate lunch and then shifted to digging post holes—our first inspection was only about footings, not ledgers or hangers.

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On paper, planning the post locations looked simple. The 3D rendering provided by 84 Lumber showed two posts at the deck end, two for the middle of the stairs, and two at the bottom of the steps.

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Translating that to the ground took more work. For the end posts, we found the deck end and set the stair angle at 45 degrees. We marked lines with string tied between stakes hammered into the dirt.

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To locate the stair posts we had to determine stair length. My geometry being rusty, I used an online stair calculator. Even with the calculator, staking out stairs took time because Sherry, my dad, and I debated the stair layout. We considered flared stairs, a platform mid-way, and other options, but the space and the presence of the AC unit left us with a simple straight stair layout.

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We shifted the string five inches away from the house for clearance and planned to plant something on the right side to buffer the steps from the AC unit. We also decided a railing section on the deck would likely become a built-in planter box.

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By 5 p.m. on Day #2, two days of work had caught up with us, so we postponed hole digging. A few days later, my dad arrived with a two-man auger from the Home Depot Tool Rental Center—Deck Day #3.

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After a less-than-fun manual post-hole experience on the patio fence project, we decided to rent an auger. It was $60 for four hours (or $85 for 24). I dug a shallow guide mark for each hole so the auger bit would start in the right spot.

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The auger starts like a lawn mower and, while a little unwieldy, it wasn’t too hard to use. It took two people: one to steady and guide it and one to control the throttle. We let the machine’s weight do the work and pulled the auger out occasionally to clear dirt. Note: always call your local utility-locating service before digging to avoid hitting wires or pipes; we called Miss Utility early in our planning.

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Using the auger was tiring—my pictures show I worked hard—but the machine saved a lot of time. After each auger pass we cleaned up the hole manually with a shovel and post-hole digger to reach the required dimensions. We rented an 8″ auger bit by mistake but needed 12″ holes for inspection, so we widened them manually.

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Once tidied and measured, the holes met inspection requirements: 12 inches wide and a minimum of 18 inches deep for our frost line. We aimed for at least 21 inches to add several inches of gravel for drainage before pouring concrete.

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Digging the six holes took about two hours—fast compared to the other deck work. It was also one of the muggiest, most humid days of the summer, so we were exhausted and thoroughly sweaty by the end.

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With the footer holes complete, we can schedule our first inspection. I’m confident in the work, though inspections always make me a bit nervous—so fingers crossed. Maybe I’ll don a dapper “inspection-getting” outfit, or send Burger and Clara out to charm the inspector.

What did you tackle this weekend? Any other auger users out there, or did you dig the old-fashioned way like we did for the patio fence? The auger rental’s $60 made the work much quicker, so it felt worth it.

Psst—If you want to follow the deck story from the beginning, we’ve posted about planning it, clearing the area, getting a permit, demoing the old deck, and Day One of building.