Wood Handrail with Balusters

Cut the top and bottom 2x4 rails to the overall length of your straight run. Attach the 4x4 posts to the ends with 3" countersunk screws and wood glue through the top and bottom rails. If your run is longer than about 6 feet, check your local code — you'll likely need an additional mid-span post, centered along the run.

Leave a gap at the bottom of the rail section — like a toe-kick — by setting the bottom 2x4 up off the floor rather than flush to it, keeping to your code's minimum baluster-gap spacing.

Figure out how many balusters your run needs given your baluster width and target gap. If the count comes out odd, center one baluster on the rail's midpoint and work outward. If it comes out even, center a gap on the midpoint instead and work outward from there.

Starting from your centered baluster (or the one next to your centered gap), add the remaining balusters at your calculated spacing. Cut a spacer block at that exact spacing and use it against each baluster as you go — it's faster and more consistent than measuring and marking every single one.

The pocket holes for the balusters will show on the inside face of the rails. Cover them with 1x4 trim, glued and nailed on — it also gives the inside a clean, finished look instead of exposed joinery.

If your handrail turns a corner, use the corner post as the shared end for the next straight section and repeat the process.

Attach the handrail to the floor and wall or structure it's protecting. Every installation is different — ledger screws into framing, post bases bolted to a deck, or concrete anchors into a slab — so choose hardware rated for your actual mounting surface and the load a handrail needs to carry.