Laying Out the Deck

To locate deck footings when the yard slopes away from the house, you must first measure out from the house along a level line, then down to the ground along a plumb line. This is difficult to do using mason's lines and batterboards. Instead construct the outside frame of the deck, temporarily support and level it, then measure down for the footings.

This method may seem tedious, but actually it will not consume a lot of time. You must build the frame anyway, so you might as well do it now.

Though the supports are temporary, make them sturdy because they need to hold the frame still while you work on it. You will reuse one of the supports later. The 4x4s used as temporary supports can be used later as permanent posts for the deck.

Prestart Checklist

Time
Four or five hours to build a frame, support it, and measure down to locate the footings

Tools
Tape measure, framing square, mason's line, hammer, circular saw, drill, sledgehammer, plumb bob, post level, carpenter's level or water level

Skills
Measuring and cutting boards, fastening with nails or screws, working on a slope

Prep
Install the ledger; consult the framing plan to determine the exact dimensions for the outside joists and the header

Materials
Joist lumber, 16d galvanized nails or 3-inch deck screws, stakes, 4x4s for temporary supports, 1x4s for bracing