How to Build a 2×4 Deck Rail on a Concrete Patio – After setting the 4×4 posts on the concrete anchor rods, install the 2×4 deck rails and 2×2 balusters.
This project is continued from Part 2.
Attach the 2×4 Rails to the 4×4 Deck Posts
I pre-drilled the screw holes with a slightly smaller diameter bit than the screw to prevent the deck rail wood from splitting.
Next, fasten the 2×4 top deck rail to the 4×4 posts and verify the top rail is level.
It turns out the concrete deck is sloped away from the house (this is normal for rainwater runoff) and the left post is about 1/2 inch too high. I used the carpenters level to mark the proper height and angle as shown and cut the post to the correct length on the Mitre Saw. This is an instance where using wood screws makes disassembly and corrections easy compared to nails!
Locate the bottom rail at least 2 inches high (to avoid catching leaves) and set a single wood screw only on the left end – this allows opposite end to rotate for leveling. Level the right end as shown and fasten the two screws. Then fasten the remaining screw in the left end.
The 2×4 face rail is attached with 3-1/2 inch screws evenly with top rail as shown. The balusters are laid out to show the overall progress.
Attach the Balusters to the Deck Rail Frame
So far, the deck rail frame is just sitting on the concrete anchor pins. It’s a snug fit, but the frame can be removed by lifting straight up such as not to bind sideways on the pins. Since frame is small, I lifted it off the anchor pins and laid it face down on the patio for easy access.
To attach the balusters to the frame:
- Pre-drill the screw holes in the balusters, otherwise the 2×2 post will split.
- Screw the 1st baluster to the frame with 2-1/2 inch corrosion resistant deck screws.
- Use a 2×4 block to set the gap to the next baluster and fasten it with screws.
- Move the 2×4 block to the next position, fasten the next baluster, repeat.
Move the 2×4 spacer block over and attach the next baluster. Repeat for the remaining balusters. Note the baluster drip edge is facing the bottom 2×4 rail for a pleasing look.
The newly assembled deck rail section is shown with the main deck rail (red) for comparison:
Deck Rail Final Assembly
The deck rail section is set on the concrete anchor pins. At this point, the deck rail is very rigid and fits snugly on the pins; any attempt at sideways movement will cause the 4×4 end posts to catch and bind on the 1/2 inch steel anchor pins.
Side view of the deck rail:
To plumb and deck rail and ensure there will be no movement, I used Simpson Strong-Tie angle connectors and screws to attach it to the 4×4 deck rail post to the 4×4 stairwell post.
I plumbed the deck rail using a level – it needed to lean forward about 1/2 inch to be vertical.
Then fastened the metal angle plate as shown in the next photo. Doing so fixed the deck rail in place very securely – almost no wiggle in any direction with heavy force.
Here’s how the completed deck rail looks. Note the short 2×2 section on the lower right to elevate the PVC condensate line.
Front view of the finished deck rail.
I’ll stain the new deck rail when the weather warms up in the spring.
Thanks for reading!
Bob Jackson
