Columns support the porch roof, and 4-inch-by-4-inch-thick posts are one of the most common materials used to bear the load. To thicken the appearance of the posts, wrap or box in the columns with pine or cedar boards. Because the wrap is superficial, it is nailed to the column post without fastening to the beam above or floor below. Space all nails approximately 4 inches apart, staggering them slightly up or down at the corners to prevent hitting one nail with another. Porch railings should be removed first.
Measure the length of the post from the floor to the beam.
Measure two 1-inch-by-4-inch and two 1-inch-by-6-inch boards to that length, and mark them with a pencil.
Hold the lipped edge of a carpenter's square against the edge of a board with the perpendicular edge of the square straight across the face of the board. Align the 90 degree corner of the square with the pencil mark. Trace the edge of the square straight across the board with a pencil. Repeat to mark each board.
Cut each board straight across at the marks with a circular saw.
Stand one 1-by-4 on end against the left side of the porch column as it faces you. It doesn't matter which side you choose in relation to the house, as it is just your starting point. Align the edges of the board with edges of the post.
Hammer 8d finishing nails through the face of the board and into the post from top to bottom along both sides.
Stand one 1-by-6 on end against the back side of the post, on the right perpendicular side of the nailed 1-by-4. Align the edge of the 1-by-6 with the edge of the 1-by-4, making a straight corner from top to bottom.
Nail through the 1-by-6 and into the end of the 1-by-4 from top to bottom. Fasten more nails through the face of the board and into the post approximately 1 inch in from the opposite edge of the board. The 1-by-6 will be slightly wider than the post, forming a lip.
Lay a 1-by-6 flat on a work surface. Set a 1-by-4 up on a long, narrow edge, and butt it against a long edge of the 1-by-6. Nail through 1-by-4 and into to the edge of the 1-by-6.
Stand the nailed board assembly upright with the 1-by-4 on the side of the post column where the lipped edge overhangs, and the 1-by-6 on the perpendicular side of the post. If the first 1-by-4 board that you nailed to the post is on your left, the 1-by-4 of the nailed assembly that you are ready to install should be on the right. The 1-by-6 of the assembly should face you.
Nail through the left side of the 1-by-6 and into the end of the first 1-by-4 that is fastened to the post. Nail the right side of the 1-by-6 to the post approximately 2 inches in from the corner.
Add more finishing nails through the lip of the first 1-by-6 that you nailed to the post and into the end of the 1-by-4 of the assembly, completing the box around the post.
Countersink each nail by tapping the head lightly with a nail-set tool and hammer.