How deep does a deck footing need to be?
How deep does a deck footing need to be?
12 inches deep
By code, the bottom of a footing must be at least 12 inches deep and below the local frostline—whichever is deeper—and bear on stable, undisturbed soil that is free of organic matter. And the code requires a minimum compressive strength of 2,500 psi for the concrete.
How deep and wide do deck footings need to 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.
How deep should posts be in the ground for a deck?
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.
What diameter should deck footings be?
A good size for a common backyard deck is a 10″ or 12″ diameter for the sonotube and a 20″ base diameter. Of course, you can get a 24″ base size and it will spread weight over an even greater surface area. The one down side to this is the extra digging involved.
What is the code for deck footings?
Footings need to be at least 12 inches below settled soil to prevent lateral movement. In addition, they need to be dug below the frost line, which varies according to climactic zone.
How thick should deck footings be?
Assuming a minimum soil bearing capacity of 1,500 psf, 8-inch-diameter concrete piers bearing on square footings measuring 2 feet on a side and 9 to 11 inches thick are adequate for most single-story decks where beams are spaced 14 feet apart or less and joist spans are 14 feet or less (see table below).
What size sonotube for a deck?
A good size for a common backyard deck is a 10″ or 12″ diameter for the sonotube and a 20″ base diameter. Of course, you can get a 24″ base size and it will spread weight over an even greater surface area.
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 many footings 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.
Can I use deck pier blocks instead of footings?
Pier blocks can be used instead of footings for a ground-level deck not requiring permits. Piers blocks can also be used if the frost level depth is less then the height of the pier block.
What diameter sonotube do I need?
The rule-of-thumb is to use a tube diameter 3 times the post width, therefore use a 12” diameter Sonotube for a 4×4” post.
Why to use sonotube?
Sonotubes are designed to alleviate both sources of delay by making these disposable molds easy to place and easy to remove. As noted, Sonotubes are also made from a type of reinforced cardboard. This makes each tube relatively lightweight, allowing anyone (including a DIYer) to work with them safely.
Can you build deck without footings?
Over Gravel. Grading a flat spot for the deck is necessary, even when alternative building methods are used. Add a level layer of gravel for drainage, and you can build a deck that rests on the surface without footings.
Why use sonotubes?
Why Use SonoTubes? Footings and piers are designed to support the weight of a deck through all types of weather and stress. SonoTubes create smooth-sided piers that resist uplift caused by frost; make it easier to estimate how much concrete you will need; and hold moisture in the curing concrete longer, resulting in stronger piers.
