Plan to evenly space posts around the perimeter of your deck, such as every 6 feet (1.8 m). [substeps] Keep in mind that some posts may be larger if they're going to have a gate attached or support stair handrails.
[header] How to build a deck railing [title] Count how many posts you will need. [step] Your deck might already be supported by posts, especially if it is covered. If not, you'll need to install these so that there will be something to support the railings.