When adding a deck to your home you must also add a deck ledger board. A deck ledger board is affixed to the home. This is the first part of the deck to be installed and serves as a reference point for all of the other supporting structures of the deck. There are different techniques for attached the ledger board depending on whether the home’s foundation is wood or masonry.
Step 1 - Position the Ledger Board
Look for any obstructions where the board will be placed, such as water faucets, electrical wiring or vents. If you have any of these then you must plan to place the ledger board in a way to accommodate them. Put the ledger board below the door threshold allowing room for the thickness of the deck materials to be installed. You may want to place it lower if you intend to step down onto the deck from the doorway. Add 1 ½ inches to each side of the deck width so that hangers can be connected for the joists. Use a level to mark the placement of the top side of the ledger board. Choose a board that is straight and one piece if possible.
Step 2 – Cut Away the Siding
In order to attach the ledger board securely to the house you need to remove a section of the siding. You can reinstall aluminum or vinyl siding after the deck is completed. You will need to use a circular saw if you have wood or concrete siding. Set the blade to cut only through the siding and not into the underlayment. Cut away enough of the siding to install flashing over the board.
Step 3 – Choose the Fasteners
The fasteners must be able to handle the load of the weight of the deck to keep it from coming away from the house. Usually ½ inch lag bolts with washers are used. They will have to be 4 to 6 inches long to go all the way through the board to the house framing. The fasteners must also be intended to work with pressure treated deck lumber.
Step 4 – Attach the Board
Hold the flashing in place. Use your marking and the level to be certain the board is straight. Install the fasteners through the board and directly into the wall studs. The fasteners should be place 16 inches apart on center. Alternate top and bottom placement.
Step 5 - Seal the Flashing
Push the flashing down and around the ends to drain water away from the foundation. Caulk any overlaps in the flashing and at the bottom and corner of the board.
If you are installing the ledger board to masonry then you will need to take the extra steps of drilling holes in the ledger board. Then drill into the masonry with a hammer drill and inserting expansion anchors into the holes. Use a hammer to tap them in flush with the masonry. Then the bolts can be put through the board and into the holes and secured.
When you install the ledger board correctly you have made the important first steps in building a strong deck that will last for years.