Deck Post Sizing
Deck posts are usually 4 feet x 4 inches, 6 feet x 6 inches or 8 feet x 8 inches as determined to be appropriate for the expected load. After determining the width, the maximum deck post height must also be determined. This also depends on the type of wood used.
What size should deck support posts be?
The posts should be a minimum 4×4 size and be solidly anchored to the deck joist and rim joist of the structure. Use two through-bolts and a metal tension tie for the upper bolt connection.
How deep should a deck post be in the ground?
Set footers a minimum of 6” below the frost line for your area to prevent movement during freezing temperatures. Pour about 6 inches of all-purpose gravel into postholes and pack the gravel tight by using the end of a wooden post.
How high should 4×4 deck posts be?
According to the American Forest and Paper Association, or AFPA, a four-by-four post made from Douglas fir or southern pine should be no higher than 10 feet, and at that height the post can support no more 36 square feet under a load of 50 pounds per square foot.
Should you use 4×4 or 6×6 deck posts?
Deck posts must be a minimum of 4×4 according to the IRC but many jurisdictions require a 6×6 post as a standard. To avoid code violations, many deck builders choose the 6×6 even if the 4×4 is acceptable.
Should deck post be set in concrete?
A deck post should always be placed on top of footing, not inside concrete because it can break. The photo on the left shows a post set in a bracket that has been mounted to the top of a footer. The photo on the right shows a post that has concrete poured around it, which can lead to a crack like you see here.
How many posts do I need for a 12×16 deck?
As a guide, if you choose to use 20-foot boards, you will need to purchase 22 of these boards. Similarly, 18-foot boards will require 24 boards, 16-foot boards will require 27 boards, 14-foot boards will require 31 boards, 12-foot boards will require 37 boards and 10-foot boards will require 44 boards.
How far apart should footers be for a deck?
How Many Footings Will I Need? The standard rule for footings is that for a basic deck, the larger the beam and footing size, the fewer footings you’ll need. If you’re building a simple deck, footings and posts should be placed 8 feet apart on average.
What is the maximum distance between deck railing posts?
U.S. building code requires support posts for the rail structure to be no further apart than 6 feet on a deck with 4×4′ deck rail posts and no more than 8 feet apart for decks with 6×6′ deck rail posts. Posts should be no further apart than 5.5 feet on stairs.
How many posts do I need for a 12×12 deck?
For an attached 12 x 12′ deck, you’ll need at least 3 footings, plus at least 2 more if you’re planning on building stairs with it. If your deck will be a different size, it’s easy to figure out how many you’ll need.
What accounts for roughly 90% of all deck collapses?
About 90% of deck collapses occurred as a result of the separation of the deck ledger board from the house, allowing the deck to swing away from the house. It is very rare for deck floor joists to break mid-span. Many more injuries are the result of rail failure, rather than complete deck collapse.
How many posts do I need for a 8×12 deck?
The larger 12-foot side will have a post spacing of 6 feet at a minimum code requirement. That makes a total of eight posts that need to be installed on this average size deck.
Do deck post need to be notched?
Notching a post does not weaken the structural integrity of the wood support post because the load for the deck is transferred down through the post to the footings. The upright notched section of the post acts stabilizes the beam.
How many posts do I need for a 10×10 deck?
A freestanding 10′ x10′ deck needs 4 posts, supporting two pairs of 2-ply non-incised 2×8 beam, upgrading the beam to 3-ply using incised wood.
