Building a Deck:
Preparing Siding for Ledger

The deck ledger board is attached directly to a house wall after the siding's been cut away, and it supports one side of a deck.
 
The first steps in attaching the deck ledger board are determining where the top of the deck hits the house, where the deck ledger board goes and where the siding needs to be cut.

Checking House Framing

As a general rule, it's best to anchor a deck ledger board directly to an existing rim joist in the house framing.
 
The rim joist is found on the outside edges of the home's floor framing, so if the deck goes at the same level as the existing home floor the rim joist can support the ledger board.
 
If the deck is to be located higher on the wall, you can secure the ledger board to the studs inside the wall.

If the deck is to be located along a section of poured concrete or concrete block, you can secure the ledger board to it but you must drill into concrete with a masonry drill, insert masonry anchors and then lag screw the ledger board into those.

Marking Top of Deck on Siding

To determine where the deck ledger board should go, first mark on the siding where you want the top of the deck to end up on the house wall.

It will usually be a point the same height as the interior floor and just below the threshold of any existing or planned door leading onto the deck.

Set a level with one end against the mark, hold it level along the siding and draw a line representing the top of the deck.

Extend the line in each direction to the full width of the deck. That gives you the top horizontal cutting line for the ledger board pocket.

Marking Siding for Deck Ledger Board

To mark the bottom horizontal cutting line, first measure down from the top line for the thickness of your deck boards (usually 1-1/2 inches, the thickness of a 2x4 or a 2x6).

Then from there, measure down for the height of the ledger board, in this case another 9-1/2 inches (the height of a 2x10 board).

Make the same measurements on the other end of the ledger board and snap a chalk line between to represent the bottom cutting line for the deck ledger board.

Removing Siding for your Deck Project

Use a circular saw to cut along the horizontal cutting lines, with the blade set at a depth that won't cut into the sheathing below the siding.

After making the top and the bottom cuts, use a jig saw to make the vertical cuts on the ends.

Then pry up the nails holding the boards in the cut-out area and pull the boards off.