How to Build a Deck Foundation
By: Danny Lipford
Building a deck starts with a sturdy foundation. The foundation needs to be able to easily support the weight of the deck materials plus the live load of those using it. Here are the steps I take when constructing the foundation for a deck:
- Start by laying out the location of the deck foundation so it’s square and level with the house and at the proper height to line up with the interior floor.
- Mark the location of the footings for the deck on 8’ centers, and dig 2’x 2’ holes that are 2’ deep.
- Cut and tie together a grid of metal rebar that will be embedded in the concrete, and position it in the hole several inches above the bottom.
- Drive a grade pin made from rebar in the hole to mark the exact depth the concrete will be poured.
- Fill the holes with concrete to the proper height. Steel straps are embedded in the concrete to act as tie downs for the deck framing.
- After the concrete has set, lay a concrete block foundation
- Framing begins with pressure treated 2”x6” blocks caps on each column.
- 6”x6” treated sills are positioned on top of the blocks to support the floor joists.
- 2”x10” floor joists are placed perpendicular to the sills and nailed in place.
Linking all these elements together from the concrete up provides a nice, rigid platform to support the heavy deck. Watch this video to find out more.
- How to Install Deck Boards (video)
- How to Choose Between Composite and Wood Decking (video)
- How to Build Deck Stairs (video)
- How to Build Deck Handrails (video)