Dig the holes and set the posts
Drive a 16-penny nail in the sill of the house at the beginning point of the deck. Tie the heavy string on the nail and pull it out to about 12 feet. To make certain it is perpendicular to the house, measure out from the nail and mark the sill at 36 inches.
Mark the string at 48 inches. Put the end of the measuring tape on the 36-inch mark and pull it over to the 48-inch mark on the string. Adjust the string until the measurement between the two points is 60 inches. Pull the string tight, drive a stake in the ground and tie the string to it. Measure from the nail in the sill, and make a mark at 24 feet and repeat the process with another piece of string.
Mark the two strings at 10 feet away from the house. Drive stakes in the ground on these marks and tie a string connecting the two stakes. Mark that string at 12 feet and drive a stake in the ground there. Dig 24-inch deep holes in the ground everywhere the stakes are in the ground with the post hole diggers. Make the diameter of the holes at least 12 inches. Do not remove the strings yet.
Set the posts in the holes, mix the concrete in a wheelbarrow according to the manufacturer’s instructions and dump it in each post hole around the posts. Place the carpenter’s level on the posts vertically to plumb them straight up and down. Let the concrete set before proceeding.
Floor joists and deck floor
Attach two 2x8x144-inch (12-foot) pieces of lumber to the sill of the house with 3-inch lag screws, a socket and ratchet. Next, secure joist hangers on either end of the two pieces of lumber with the 2-inch deck screws. Measure out from where the two 12-foot pieces of lumber meet in the center and make marks at 1-3/4 inches.
Secure a joist hanger on the right mark so the left inside of the hanger is on the mark. Next, secure one on the left mark so the right side of the hanger is on the mark. Secure them with 2-inch deck screws.
Measure and cut a 2x8-inch piece of lumber to go from the sill on the house to the posts of the proposed deck. Set one end in the joist hangers and secure them to the hangers with 1-1/2-inch deck screws. Secure the other end of the lumber to the posts with the 3-inch deck screws.
Cut two pieces of 2x8-inch lumber to meet in the center of the center post and run to the outside edge of the lumber on the outside posts. Secure them to the posts with 3-inch deck screws. Hang joist hangers on 16-inch centers on the lumber on the house and these two pieces.
Determine the distance between the lumber on the house and the inside of the lumber opposite it. Cut floor joists from the 2x8-inch lumber, put them in the joist hangers and secure them with 1-1/2-inch deck screws. Install the deck floor parallel to the house with the appropriate fastener, splicing them in the center of the deck.
Things You Will Need
- 16-penny nails
- Heavy string
- Wood stakes
- Post hole digger
- 3 pieces of 4x4-inch posts
- Concrete mix
- Carpenter’s level
- 2 pieces of 2x8x144-inch (12-foot) pieces of lumber
- 3-inch lag screws
- Socket and ratchet
- 2x8 joist hangers
- Variable speed drill
- Philips head screw tip
- 2-inch deck screws
- 1½-inch deck screws
- 3-inch deck screws
- Deck floor material
- Countersink the screw heads on the deck floor.
- Cut the posts before attaching the deck floor if desired.