If you are adding a deck to your house, you need to install footings to anchor it firmly to the ground. These footings prevent frost heaves from moving the posts that hold up the deck, which in time can damage or destroy it. Although footings for the deck stairs are not required in all locations, they are always a good idea. Taking a little extra time now to secure the stairs as solidly as the rest of the deck will prevent problems and expenses later.
Things You'll Need
- Spray paint or 2 stakes
- 1 Board, 2-by-4
- Concrete mix
- 2 Posts
Mark the spots on the ground where the stair posts will be situated. Use spray paint or stakes.
Call your utility companies. Ask if electrical lines or pipes are buried in these places.
Dig holes for the stair footings at the places you marked. The holes should extend more than 6 inches below the frost line. This will prevent frost heaves from shifting the alignment of the posts. If the ground does not freeze in your area, then the footing holes must extend at least 18 inches below the surface. The holes should be at least 12 inches across.
Pour gravel into the holes to a depth of 6 inches. Do not exceed 6 inches. Pack the gravel down, using a length of 2-by-4 board.
Mix up a batch of concrete according to the manufacturer’s instructions. For such a small amount, hand mixing in a wheelbarrow will be easier and cheaper than using a cement mixer.
Set one of the posts into one of the holes. Pour the concrete into the hole around the post. Use a level to make sure that the post stands perfectly plumb.
Tips & Warnings
- Wait three days before continuing construction of the deck stairs or putting any other kind of pressure on the posts. Some types of quick-drying concrete will require less drying time.
- Use treated wood for the posts. If you do not, they will be in danger of rotting after they are placed in the ground.
- If you are in a location where the frost line is far below the surface of the ground, then you do not need to fill the entire footing hole with concrete. Pouring 6 inches of concrete will be enough.