Make gridwork balusters for your porch

This is the gate I made, with the small gridwork pattern I copied later for the balcony railing system. Japanese-style grillwork like this is called kumiko.

Back in 2016 I designed and built a Japanese-style gate, which appeared in Fine Homebuilding magazine this past year, and appears every day in my backyard (the best part). I visited the Portland Japanese Garden for inspiration, as well as a few websites and Google images. Once I settled on the design for the gridwork panel in the door, I realized it would also work at larger scale for the railing system on an upper balcony that sticks out of the house, just across the backyard patio.


Well, this year (2018) I finally got around to those rails and balusters on the balcony, which used to be that generic contractor grade you see on condos and apartment buildings. Fine for what they are, but a combination embarrassment/challenge for a woodworker like me.

I started by pulling down all the wobbly posts and rails and taking it all to the dump. Then I covered the joists with TimberTech, the same excellent composite decking I used on the deck in the backyard, and screwed new posts onto the deck using these long, awesome, decorative screws designed for thick timbers, from Home Depot. The posts are cedar, as is everything in the new rail system. I added top rails to the posts, and screwed a composite deck board onto the top of each one.

The next key part was adding a bottom rail, with would complete the rectangular frame where each panel of gridwork would go. To keep those bottom rails parallel to the top, I just made a spacer stick, which I pressed the lower rail against when screwing it into place. BTW, I held it in place with a combination of angled screws and these decorative angle pieces, which look nice.

As for making the grillwork balusters, I started with 1-1/2-in.-square cedar stakes/balusters you can buy at the home center. Then I did some drawing to scale up my original, small grillwork to suit the thicker pieces. You want to get the horizontal spacing adjusted so there are even spaces at each end.

Then I cut all the pieces to fit inside the rail system. Your spaces will probably vary from post to post, so keep track of which grid pieces go where. The vertical lengths should be consistent, since you used that spacer stick to set the lower rails. As for the rest of the process, I’ll let the photos do the talking.

I started by notching the vertical pieces. Those only get four notches each, two near the bottom and two near the top, so you can do those with a dado set, using your tablesaw’s rip fence as a stop. They key is to make each notch narrower (1-3/8 in.) than the thickness of the cedar pieces (roughly 1-1/2 with a lot of variance). You’ll see why later. As for the depth, you should try to nail that, exactly halfway through the thickness.
To cut the notches in the horizontal grid parts, I created a jig like this one, which clamps to your miter gauge. You just cut a notch in the fence, and plane a small stick to fit in it. Then you move it over and cut another notch in the fence that is the same distance away that you want each vertical piece in the grid.
You cut the first notch just like you did before, using the rip fence as a stop. Then that first notch goes over the stick you inserted in the fence jig, like so. The tricky thing is that the typical dado set stacks up just over 3/4 in. wide, and you need notches that are 1-3/8. So you bump your already-cut notch against one side of the little key and make a cut…
… and then bump it up against the other side of the key to cut the rest of the notch. You continue this way as you work your way down the whole row of notches. The jig ensures even spacing. Unfortunately, it’s also pretty sensitive to how much side pressure you apply against the key, so check every third notch to be sure the the widths are staying consistent, and go back over them if needed.
The last step before assembly is to plane the sides of all the pieces to 1-3/8 in. wide, so they all fit into their notches. Do a big dry-fit to make sure they do. Make sure they all go in easily, and run tight pieces through the planer if needed, marking where they go in the grid. When everything goes together nicely, you can brush glue into the notches and assemble the grid for real.


Installing the panels was easy. I just screwed strips to the rails and the posts as a stopper at the back edge of the gridwork, using the spacer in the next photo to maintain the right inset.


Then after the grid goes in, you screw identical strips in front of it, trapping it solidly in place. Works great!
The new rail system looks awesome. My last step will be to tack on cedar planks near the top of the joists, to cover the ends of the deck boards (and that patch of dry-rot!). I’ll put spacers behind those thin cedar planks, to keep water from getting trapped there.