There are many features you can add to your deck to improve its appearance and functionality. Adding a handrail is one of the simplest ways to do this -- it finishes your deck with clean lines, and gives people something to hold on to when navigating your deck. A solid handrail can even make it possible for a physically challenged person to enjoy your deck space with you. Installing a handrail to a deck post is a simple task that can be accomplished by most homeowners in just a few hours.
Determine which posts you want to support your handrail. Measure the distance between these posts. Also, use a carpenter's level to see if there is any difference in height between the posts. This can be accomplished by laying a piece of 5 by 10 cm (2 by 4 inch) timber on top of both posts, then placing the level on the board.
Cut a 5 by 10 cm (2 by 4 inch) board to the length between the outsides of the posts. If the railing will be at an angle, place the board in place -- oriented vertically, so that it is 10 cm (4 inches) tall and 5 cm (2 inches) wide, flush with the tops of the posts, to mark the angled overhang at the ends. Use a circular saw to cut away the overhang.
Attach the 5 by 10 cm (2 by 4 inch) voard to the inside of the posts, flush with the top of the posts. You can use either wood screws or nails to attach this piece.
Cut a 5 by 15 cm (2 by 6 inch) board to the length between the outsides of the posts. Lay the board on top of the posts and the two-by-four and fasten to both using wood screws or nails. Sand the top of the railing to help prevent splinters.