Your local building code will have a maximum allowable distance between steps. Take the height difference between the top of the deck and the landing (which should be a 4" and reasonably level concrete pad) and divide that distance by the maximum distance allowed between steps.
The diameter of the holes for your deck piers is not a number pulled out of the air. You may get the answer from your building inspector or you may have to consult with a seasoned architect or structural engineer.
Concrete piers can support a deck, porch, house or barn in all but the softest soils. You must do some calculating to make sure the piers support the weight without sinking or heaving when the ground freezes.
If you don't set the post in concrete for a fence, it will have much less lateral reisistance and can lean. For a deck, few bolted attachments provide the lateral resistance that you really need in the long term (wood shrinkage, vibration and bolts loosening).
knk concrete offers a wide variety of construction services within the commercial & industrial sector. with the soaring costs of construction, protecting our clients investment has become only more important.
UpCodes offers a consolidated resource of construction and building code grouped by jurisdiction.
Install the precast concrete pier footings on the top of the ground. To support your deck, purchase precast concrete piers with sockets that accept 4" x 4" treated wood posts.
This Concrete Pier Block with Metal Bracket is ideal for building raised decks, walkways and floors. It is durable and offers up to 1,900 psi compression strength.