In April, the marriage team at our church hosted the Marriage Ministry Conference, a conference for marriage pastors and ministries. They asked our set design team for an illustration, and our volunteers came through big time! The request? A 40′ wide 10′ tall domino wall made from 2×4’s (video at the end). We received a lot of questions following that keynote, and I hope this answers most of them. Email me or leave a comment if you’d like any other details.
The most common question is simple to answer: how many dominos. The 10′ wall used between 3000 and 3200 dominos. Each domino is roughly 1.5″x3.5″x7″, the “roughly” being part of the reason why I don’t have an exact number.
The “how” will answer just about everything else, so let’s jump right to it. The basic construction of a domino wall is easy to find on youtube, and here’s a model of the arrangement. It’s not too complicated, but practice building this on a small scale to understand the structure. From there, the name of the game is patience, because after you figure this out, you have to cut your dominos.
Figure out how many dominos you will need… approximately. See, 2×4’s are cheap, and they’re not precisely cut (they won’t be exactly 1.5″x3.5″). So, while the length of each domino needs to be about 7″ (twice the width), the width is not consistent, and that means any attempt at calculating the exact number is foiled by inconsistent 2×4’s (jerks). I used Sketchup to model our wall to the size we needed (10’h, 40’w) and estimated 3276 “dominos”. At ~13 dominos per 8′ 2×4, that means 252 2×4’s.
Once you figure out how many you need, use a fence stop on a miter saw to cut “consistent” dominos. Remember, the jerks are very inconsistent, and your fence stop might shift as well (check it often). We had 3 different saws running, and the dominos ranged from 6 7/8″ to 7 1/4″ long. These small variations will happen, and we’ll get to how to deal with them. You could be a stickler for accuracy, but if your wall is of any considerable size, you’re cutting thousands of these things. Relax. It’ll work out. Cut more than you think you’ll need so you can be sure you’re ready to build.
Construction. We started by building a few test segments. The first was a 10’h x 5’w section to test stability at height; the second was a smaller one to test how to trigger a fall. Here’s a quick teaser of the final product.
I mentioned volunteers early on, and I hope you noticed I couldn’t run 3 miter saws by myself. In fact, I had shoulder surgery the week after we began cutting 2×4’s. A volunteer team of less than 10 people cut and stacked over 4,000 dominos. That same volunteer team came in late on a Tuesday night to construct the wall in just under 2 hours for it to be ready Wednesday morning. They’re amazing and humble, and I’m blessed to serve with them.
A few final notes before the video. First, your wall will likely bow and bend a little. This is ok so long as your dominos fully overlap; our 10′ tall wall didn’t wobble (see the gallery) despite a significant bow. Second, pay special attention to the vertical end pieces. The varied widths/lengths will cause the end to lift or sag; use longer or shorter pieces to adjust. Lastly, we triggered the collapse by drilling a hole in the bottom 3 dominos on the end and tying black rope through those three for our stage manager to pull. You could trust to a domino trail to start the collapse, but we had to be sure the illustration would trip correctly.
Here’s an iPhone video of the illustration as seen from the balcony. Enjoy!