December 03, 2021
A solid, weighty deck frame is the heart of building a deck. After completing this step, you will have a frame to add deck materials. Safety features such as railings, stairs, etc., and even other decorative items such as planter boxes and benches.
In most areas, decks that are less than 30 inches high can be installed without railings. And for safety reasons, install railings whenever possible. Which decks are higher than 30 inches. Require consultation with your local permitting department for a building permit. The frame of the deck runs along the side of the house and is attached to the house on the side of the frame.
The sill plate is a two-by-ten horizontal wood member. That attaches directly to the side of the house, using the strength of the house as one of the four sides of the deck frame. House siding cannot support a ledge because it is not structural lumber and in many cases, it is not vertical.
Cut out a section of house siding that is comparable in size to the intended ledge board. In the vertical direction, the ledger board should be located directly over the top beam of the house. This is the joist where the subfloor and floor coverings are located inside the house. Place the top of the ledge board 1 inch below the interior floor to prevent rainwater from seeping into the house.
Mark the section to be cut with a pencil and use a bubble level to make sure the ledge section is level. Cut the siding with a circular saw set to the thickness of the siding. Finish the cut by gently tapping the cut line with a chisel and hammer.
Cut the flashing to the same length as the siding. Attach the flashing to the top of the siding cut out so that one side of the flashing is under the siding.
Install the ledge board in place to hold it in place. Drill 1/4-inch pilot holes at 2-foot intervals. Use a drill bit to drill each pilot hole to 1/2 inch. Use a ratchet to drive 3/8″ x 4″ lag screws and washers into each pilot hole and countersink below the surface of the ledge board.
All decks require vertical support posts to secure the deck to the ground. The support posts must be placed on a masonry base so that the deck is firmly rooted in the ground and is not subject to ground movement or erosion.
Select a straight-out distance from the sill plate to place the support posts. Cut concrete from pipes to length; they must extend down to below the frost line in your area. Dig the hole with a hole digger, leaving a few inches of height at the top so the pipe is above the ground.
Secure the metal column bases to the top of the foundation by embedding J-bolts into the concrete. While it is still soft or by screwing the bases into the hardened concrete with 1/2-inch by 3-inch steel sleeve anchors after the concrete has hardened.
Install vertical support posts with 6-by-6 lumber, cutting each post to length. Determine the length by shooting a laser level from the bottom of the mantel plate. And subtracting 9 1/4 inches to account for the height of the support beams you will install in the next step.
Install the steel post caps to the top of the support posts using the hardware provided. Locate the post cap so that when the support beam is placed in the post cap, it will be parallel to the ledge plate. Fold the two sheets together to form the support beam. Place the support beam on the saddle of the post cap and secure it with galvanized steel bolts, washers, and nuts.
The edge joists are the two-by-ten joists that form the perimeter of the deck frame. Cut the two edge joists (called the outer edge joists) so that they extend 1 foot beyond the support beams. Attach the outer edge joists to the ledge boards with deck joist hangers. Finally, secure the third edge joist (called the roof edge joist) to the two outer edge joists with joist hangers.
The spacing of the deck joists depends on factors specific to your project. Such as the predicted weight load and the type of deck flooring you intend to use. Use your pencil to mark each space on the joists. Mark the inside of the head edge joists accordingly. Install the joist hangers with 1 1/2″ galvanized steel structural attachment screws. Cut the deck joists to length, slide them into the joist hangers, and secure the joists to the hangers with the same 1 1/2″ screws.