How to Cut 4X4 Fence Deck Posts

Posts that measure 4-by-4-inches commonly are used in the construction of many different outdoor projects, including decks and fences. The posts are used as floor and railing supports around the perimeter of the deck, and as supports for fence boards. Cutting a post is often necessary to obtain the correct length or height, based on the design of the deck or fence. The 4-by-4-inch size of the lumber can deter some people from hand-sawing the posts. Consider using a faster and more efficient means of cutting the posts to size.

Cut 4X4 Fence Deck Posts
  1. Position the 4-by-4-inch post on a sturdy work surface where it will be well-supported during cutting. Consider having an assistant hold the post for safety.

  2. Mark the position on the post to be cut. Place a carpenter's square on the post so that one side of the square runs along the length of the post and the right angle is positioned at the point to be cut. Draw a line along the right angle of the square as a cutting guide.

  3. Put on a pair of safety glasses. Plug the circular saw into an electrical outlet.

  4. Place the saw on the post. Hold the circular saw with one hand and the deck post with the other. Align the front of the blade with the marked line on the post. Back the blade away from the edge of the post slightly.

  5. Pull the trigger to start the saw blade turning. Guide the spinning saw blade through the post, following the line. Allow the saw to stop -- the blade cannot go completely through the 4-b-4-inch post. Set the saw aside.

  6. Turn the post over. Align the saw blade with the groove from the first cut. Repeat the steps to make a second cut, which will finish cutting through the 4-by-4-inch post.

About the Author

Keith Dooley has a degree in outdoor education and sports management. He has worked as an assistant athletic director, head coach and assistant coach in various sports including football, softball and golf. Dooley has worked for various websites in the past, contributing instructional articles on a wide variety of topics.