Table of Contents
How deep do you dig footings for a deck?
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.
What size footings do I need for a deck?
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.
Do I need rebar in deck footing?
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.
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. Any decks higher than 24” require concrete piles 10” in diameter and 48” below grade. These footing size requirements are to ensure enough soil bearing to prevent the joist from sinking in the ground.
How many footers 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 4×4 for deck 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.
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.
Why deck posts should not 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.
What is the distance between posts on a deck?
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 thick and wide should a footing be?
Footing width can vary according to the structure, site, and conditions. Under code, generally, one-story buildings with footings on undisturbed soil with LBVs between 1,500 and 4,000 should have a minimum width of 12 inches. Two-story buildings require a minimum of 15-inch wide footings for 1,500 LBV soil.
How high should deck footings be above?
Piers should extend 4 inches or more above grade, because footings that are recessed below grade put the post-base connector at risk of being covered by backfill, and deck hardware is generally not rated for below-grade use.
How long should a footing cure before laying block?
Assuming you are using 3,000-psi concrete for the footings, you should be safe installing the anchors after 28 days in most circumstances. But there are a few things that can greatly alter the “normal” rate of strength gain: concrete temperature and the use of fly ash or admixtures.
Can I build a deck without digging holes?
Yes. It’s possible to build a deck without digging holes. This type of deck is called a floating deck, and it sits right on top of the ground without any posts or support areas that you’d dig down into the ground [to secure].
Will deck blocks sink?
The deck blocks can sink if the soil under them erodes for some reason or the weight is unevenly distributed. That’s why it’s a good idea to use more than less. Especially in loose soils or wet conditions which requires more weight distribution.
How deep should deck posts be grounded?
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 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.
What material do I need for a 12×12 deck?
You will need 18 boards of 2-by-6-inch lumber or nine 2-by-10 inch boards to build the joists, also known as the beams. You should purchase an additional 25 percent wood to allow for framing pieces and waste.
How far apart should deck blocks be?
Space the deck blocks at 4′ to 6′ intervals to offer the frame good support.
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.
