Building a Deck On a Sloped Site

two men measuring and leveling

A deck attached to the house is quick to build and makes efficient use of materials. The angled corner of this design adds an attractive, space-saving feature that requires only about an extra half-day's labor.

Projects in Sloped Site

Framing the deck
A ledger board provides a secure way to attach a deck to a house. It also functions as an ideal starting place for laying out the site. After the ledger is installed, all layout measurements start from it.

Once the ledger is set, reference down from it to the ground and lay out the post locations. Where the deck has an angled corner, two posts must be placed at a corresponding angle. Fortunately these two footings can be off by an inch or two without weakening the deck structure.

The beam in this design rests on top of the posts. You may prefer (or your building inspector may require) a sandwich-type beam. This deck uses the simplest type of beam -- two 2x10s fastened together.

Building stairs
If the deck is only 1 or 2 feet above fairly level ground, you can build simple stairs using precut stringers available at home centers. If the deck is higher or the ground slopes, careful planning is required to make sure that all the steps (including the bottom one) are the same height. This chapter presents complete instructions on how to build the stairs.

Working on a slope
A site that slopes away from the house presents challenges for a deck builder. Extra care must be taken to ensure that posts are plumb and the deck is level.

If a slope is severe, special measures may be needed to keep the footings from slowly sliding down the hill. In extreme circumstances the footings may have to be connected to the house's foundation; hire a professional for this type of work.

For safety and convenience work with at least one helper whenever possible.

One Hour or Less

Three simple projects to cross off of your to-do list -- just print these instructions and begin!