With my deck holes dug and approved by the county inspector, it was time to fill them in. I followed the same basic approach I used when setting fence posts last year: add a couple of inches of gravel to the bottom for drainage. Local deck pros recommended gravel under the concrete footings, and since our holes were at least 21″ deep, adding 2–3″ of gravel still met the 18″ minimum depth required by the county.
As I poured the rocks in, some dirt scattered and a few tiny frogs started hopping out. They were so well camouflaged I didn’t notice them until they moved, but I rescued each one before continuing with the gravel.
I checked the other holes carefully for wildlife before adding more rock. Still, I missed one big toad until it announced itself. Once I spotted him I scooped him up (with my bare gloved hands) and moved him to safety—a fun little nature lesson for Clara, who watched from behind the sliding glass door.
I like this shot not because I’m playing iPhone paparazzi, but because I imagine Clara giving Burger a little biology lesson: “See what we have here, young chihuahua, is called a frog. It goes ribbit ribbit.” They were both captivated.
Once the holes were de-frogged and had about three inches of drainage rock, I started preparing the concrete footing. Some readers suggested precast Dek-Blocks, but our county doesn’t allow them. We can use other precast concrete blocks, yet I decided to mix my own concrete. The precast pieces would have required square 12″ × 12″ holes and perfectly flat bottoms; since most of my holes were round and uneven, mixed concrete would fill any shape and level itself. Concrete had already been delivered with my lumber order from 84 Lumber, so that made the decision easier.
I mixed the concrete in the wheelbarrow. For each 60 lb bag I added water until I reached a creamy consistency and stirred it with a garden hoe—yes, I used a hoe and it worked fine. The first batch photographed was a bit soupy, so I used slightly less water on later batches. Each batch still cured solid and naturally leveled itself, making a flat surface perfect for setting posts.
Working with concrete was straightforward, but the real challenge was the heat. The county had posted a Heat Advisory, and it was brutal to be doing physical labor outside. I stayed in the shade where possible, drank plenty of fluids, and kept going until every hole had concrete—twelve holes in total, each with about eight inches of concrete at the base.
That evening, once things cooled down, I snapped a photo of the cured concrete. The next day more materials from 84 Lumber arrived: 4×4 posts I had to order after the county asked me to add more posts and girders during plan review. It wasn’t a huge order compared to the first one, but it gave me the posts I needed for the next steps.
I ordered 12-foot posts, which worked out well because my deck is only about four feet tall—one 12-foot post yields three 4-foot posts, so that was efficient. I cut and staggered them a bit to accommodate the yard’s slope away from the house.
These posts will support 2×10 girder boards that run the long way under the decking. The joists, which run the short way across the deck, will rest on those girders. The joists must line up with the ledger (which I’m calling a rim board now because it won’t carry joist weight but will provide lateral stability). To ensure accurate heights and alignment, I set temporary joists at each end and ran nylon string between them to mark where the top of the girder would sit.
With the string pulled taut, I placed a post in a hole, checked it with a post level, and marked where the string met the post—this indicated the top of the girder. My county allows either metal post brackets or notching the posts to accept the girder; I chose to notch the posts because it felt secure and matched examples I’d seen elsewhere. Using my top mark, I measured and drew the notch location so a 2×10 would sit at the correct height.
I used a reciprocating saw to cut the notches and then set the posts back in place, bracing each with stakes to keep them plumb. To secure the posts long-term, instead of just backfilling with dirt, I used Quikrete no-mix concrete around the post bases—an approved method in our county and the same approach I used for the fence posts.
After repeating the string-mark-notch-stake-cement routine for the posts on that end, I had to wait for the concrete to cure. The whole process took several hours in heat that was nearly as hot as the previous day, so I paused until things set.
The third workday was girder day. I would have liked my dad’s help for setting the 18-foot girder, but he was out of town. I clamped the girder on the notched end post and propped the other side on a sawhorse, then used that board to mark and notch the opposite post. After checking that everything was plumb and the girder had a slight slope for water runoff, I secured that post with no-mix Quikrete—the girder’s weight held the post steady while the concrete cured.
With one side of posts in place and the girder temporarily fastened with nails and clamps, I marked and set the middle post. On the longer side of the deck, the span is 21 feet, so the girder is split into two boards that butt at the middle post. I temporarily laid a joist across the middle to establish the correct height reference for that connection.
Clara remained an enthusiastic spectator the whole time—so much so that she even brought an octopus balloon to watch the action. By the end of another very hot afternoon I had six posts set in concrete and all the girder boards temporarily in place. The girders still need to be doubled (two 2×10s) for full strength, which will require another set of hands, so I’m waiting for my dad to help with that step.
After the double girders are installed, I’ll add two more posts and a girder to form the angled edge at the deck end (you can spot the two empty holes in a photo where those posts will go). Once the girders are finished I can install all the joists quickly and then start laying the decking boards. It’s been a productive few days, and even though progress is just the beginning, the big visual rewards are coming soon—joists, decking, and a finished deck are within sight.
What have you been working on lately? Any outdoor builds, hot-weather projects, or more relaxed outdoor days like the beach? I’d love to hear what you’re tackling this season.