Building a deck is a fairly simple process. Taken a step at a time it can be accomplished by most DIY enthusiasts. Deciding how you will support your deck posts and frame is one of the key factors in how long your deck will last. Traditionally, posts are set in concrete footings, but there are several options available.
In Ground Concrete Deck Supports
Concrete filled post holes are the typical method for supporting decks. There are several ways of achieving this.
Fill the bottom 2 to 3 inches of your post hole before setting the post and pouring concrete to allow moisture to run off around your post.
Fill the hole with dry concrete mix, then add water with a hose and mix it in the hole to save time. This method works well for multiple posts. Typically about a half of an 80 pound bag is used on each post.
Use a round cardboard form in your hole to build a pier. Cut the form about 12 inches long and set it even with or slightly below ground. Fill with concrete and allow to dry. Mount a galvanised post bracket with concrete screws on top of the pier to set your post in.
In dry areas, especially with decks that will not be left permanently-porches for trailers used as construction offices, for example-packed earth can support the weight of most timber framed decks.
For low, wood framed decks sometimes packing the ground and setting the frame directly on it is the easiest and cheapest option. This is not recommended for areas with poor drainage or exceptionally heavy decks that support hot tubs or other heavy items.
Tamping the earth to set a post on can also work. Make sure the area is not recently filled. You will need to cut your posts precisely to keep the deck level. Use a string level or water level to help.
Precast Deck Supports
Pyramid shaped precast concrete deck footing piers work well for small decks where digging post holes is not practical. They can also be used on almost deck if posts are set close enough together to distribute the weight evenly.
Bricks and pavers can be used for small deck footings. Make sure the soil is packed underneath. Choose concrete, rather than cinder pavers, which crumble under pressure.
If your deck is on top of a paved area, such as concrete or asphalt, simply set your legs directly on top of the pavement. If you feel you need extra support attach galvanised post brackets to the pavement with tapcon style concrete screws and set your posts in them.