For most deck applications, in most jurisdictions, the width of a footing should be 20 inches round and a minimum of 24 inches deep. It is important that the base of the footings be solid, and in many cases you will need to keep digging until you reach undisturbed soil.
Do deck posts need footings?
Large decks that are attached to the house should always have footings because they act to spread the heavy load of the deck from the surface of a support post over a large surface of the soil so the ground can adequately support it.
Should deck posts 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 far apart are footings for a deck?
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 size footing do you need for a 6×6 post?
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”.
Do deck footings need to be below the frost line?
Footings typically must extend below the frost line to prevent shifting during freeze-thaw cycles. Dig footing holes about 6 inches deeper than required. Fill the bottom of the hole with 6 inches of gravel and compact the gravel with a 2×4 or wood post.
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.
Can I use concrete blocks for deck footings?
Simply placing them on the ground or on a poured concrete pad a few inches deep usually isn’t enough to comply with codes — they must be set at least 12 inches deep in undisturbed soil. However, concrete deck blocks can be used without restriction for a freestanding deck that’s not attached to your house.
How deep do deck posts need to 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.
Should deck posts be 4×4 or 6×6?
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.
How deep should 4×4 deck posts be?
Dig post hole so diameter of the hole is 3 times the width of the post (i.e., the hole for a 4” wood post should be about 12 inches wide). The depth of the hole should be 1/3-1/2 the post height above ground (i.e., a 6-foot tall fence would require a hole depth of at least 2 feet).
Is it OK to put pressure-treated wood in concrete?
Pressure-treated wood is required whenever you attach framing lumber or furring strips directly to concrete or other exterior masonry walls below grade. Note that this requirement is only for exterior walls, as these may wick moisture onto the lumber.
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 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.
Do post footings need rebar?
Plain concrete deck foundations without rebar are acceptable under the minimum standards of construction established in the International Residential Code. However, placing reinforcing steel within footings is a relatively easy and inexpensive practice that can provide increased performance.
Do I need to put rebar in deck footings?
Most deck builders don’t place steel reinforcing rebar in footings, but in areas with expansive or other unstable soils rebar is usually required.
Do you put rebar in sonotube?
We usually recommend that a minimum of two pieces of #4 rebar be placed vertically in an 8-inch-diameter concrete pier supporting a structure. A larger-diameter pier should have four or more pieces of vertical rebar.
