Ledger Board

• The first step in building your deck is installing a ledger board to the side of the house at the site of the deck. To do this, you'll first need to remove siding from the house to make room for the ledger board as well as a layer of metal flashing.
  
  First, attach the ledger board to studs or rim joists on the house using lag bolts. Then attach metal joist hangers to the ledger board approximately 16 inches on center. Finally, nail metal flashing to lie beneath the remaining siding, and on top of the ledger board. This will divert water from the side of your deck.
  
  

Building Support

• Your next step will be to build concrete piers or posts to support the remainder of your deck.
  
  First, dig holes around the frame of your deck, staggered eight feet apart. Pour concrete into the holes to create footing that will support the posts. The posts will need to be cut to size (sitting about two feet above ground) and placed firmly in the wet concrete. Allow the concrete to dry and the posts to set in place. The posts should be level with the joist hangers on the ledger board. To check this, run string from the joist hangers at the ledger, and then run a plumb bob from the string to the ground. Finally, install joist supports on top of the posts with lag screws.
  
  Now that your support posts and ledger boards are in place, you're ready to lay the joists. These are wooden or plastic support beams, which you must nail to the joist hangers installed on the ledger board and the joist supports on top of the posts. The decking is now ready to be laid, and your deck will be fully supported.
  
  

Final Steps

• Cut the decking boards to size and screw them to the top of the joists, laying them perpendicularly across the joist beams for additional support. If necessary, sand the decking boards and finish for easy maintenance and shine.
  
  You may need to install a railing if your deck is higher than 18 inches off the ground. Check your local building codes for specifics.