Check local building codes and permit requirements
Measure the deck perimeter and determine railing layout
Mark post locations, spacing, and gate openings if needed
Gather materials: posts, rails, balusters or infill, fasteners, brackets, post caps, and finish
Gather tools: tape measure, level, drill, saw, square, wrench, clamps, and safety gear
Cut and install post bases or mount posts securely to the deck framing
Verify posts are plumb and anchored to structural members
Install corner and end posts first
Install intermediate posts at required spacing
Trim posts to the required railing height
Attach the top rail between posts
Attach the bottom rail between posts
Install balusters, pickets, cable, or other infill according to code and design
Maintain consistent spacing between balusters or infill components
Secure all connections with approved fasteners and hardware
Install a handrail if required by code
Add post caps and any decorative trim
Sand rough edges and check for sharp points
Apply stain, paint, sealant, or protective finish
Inspect the railing for stability, alignment, and code compliance
Tighten all hardware after installation
Recheck the railing periodically for looseness, rot, or damage