Table of Contents
In general, posts should be spaced no more than 8 feet apart. Some builders position them every 4 feet for a completely rigid frame.
How many 4×4 posts do I need for a 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. For aesthetic or symmetry reasons, more posts may be added.
How many posts do I need for a 12×12 deck?
Before starting to build, the first question is: How many footings do I need for a 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.
Should I use 4×4 or 6×6 deck posts?
Unfortunately, a 4×4 post may not be able to withstand the weight, causing the entire porch to buckle. A 6×6 post gives you a little more long-term stability, particularly in those colder climates. Not only does it perform better when carrying heavier loads, but it also makes the heading for your roof more secure.
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. Concrete tends to absorb moisture and wood expands when it gets wet, so these two factors combined will result in the wood breaking the concrete.
How many footings do I need for a 12×16 deck?
A standard deck will need four footings parallel to the house, but they will need to be temporarily braced by 6 inch-by-6 inch posts. Using doubled boards, you will then need to build beams on the top row of the posts to frame the edges of the deck. These must be topped with adjustable post caps.
How far apart should 6×6 deck posts be?
For Building a Deck Railing, Deck Frame, or Fence The maximum spacing of 4×4 deck posts should be 6 feet on center, while the maximum spacing of 6×6 deck posts should be 8 feet on center.
How do you calculate deck posts?
Draw a line through the mid-span of the joists. Then find the mid-span of the beam that the post supports, and extend lines from there back to the line at the joist mid-span. Find the area within the lines. To calculate the design load for the post, multiply the tributary area by the combined live and dead loads.
How wide should deck footings be?
FOOTINGS: – Poured concrete footings should be a minimum of 8” wider than the posts (4×4 post – 12” min. width, 6×6 post – 14” min. width), a two level deck or deck with roof – 24”x24”. – The bottom of the footings must be a minimum of 36” below finish grade level.
Should deck joists be 2×6 or 2×8?
In general terms, joists spaced 16 inches on center can span 1.5 times in feet their depth in inches. A 2×8 up to 12 feet; 2×10 to 15 feet and 2×12 to 18 feet. The larger the deck, the larger the joists. 2×6 joists should only be used on ground-level decks that do not require, and will not provide for, any guards.
Should you notch deck posts?
Say “No” to notching pressure-treated deck posts. We want you to build an outdoor railing system that you, your family and guests can enjoy without worrying about safety issues. In order to do so, you need to know this building shortcut is not advisable, and we recommend avoiding it at all costs.
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.
Will decking posts rot in concrete?
The post will only rot at ground level, it does not matter what you put in the bottom of the hole. A pressure treated post will last around 10 years.
How long will a 6×6 post last in concrete?
A PT post will last a long time in concrete, maybe 5 to 10 years in soil alone. I suggest you embed the post in concrete, trowel a peak around the post so water runs off, and don’t let the PT post come in contact with the ground.
Can you build a deck with 4×4 posts?
In the past, many decks were built with 4×4 support posts (also called structural posts). But these can bow seriously, even if a deck is only 3 feet off the ground. For that reason, we strongly recommend that you use 6x6s instead, even if your building department does not demand them.
How many posts are needed 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.
How many beams should a deck have?
While cantilevering can add width to your deck and eliminate the need for additional footings, posts and beams, sometimes it isn’t enough. A 20-foot wide deck, for example, would require two beams: one at 10 feet and one and 20 feet in order to support a deck with 2×8 joists spaced 16 inches apart.
How deep and wide do footings need to be?
8-Inch Solid or Fully Grouted Masonry As you can see, heavy houses on weak soil need footings 2 feet wide or more. But the lightest buildings on the strongest soil require footings as narrow as 7 or 8 inches. Under an 8-inch-thick wall, that’s the same as saying you have no footing.
Does a deck footing need rebar?
Plain concrete deck foundations without rebar are acceptable under the minimum standards of construction established in the International Residential Code. Footings with large bearing areas or unstable soil can benefit from adding rebar to prevent cracking.
How far can a 2×6 decking span without support?
2-grade 2×6 joists can span up to 10 feet 9 inches from beam to beam when spaced the standard 16 inches apart with a maximum live load of 30 inches per square foot.
