QA

Question: How To Build Deck Footings

How deep should deck footings be?

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.

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. 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 do you attach footings to a deck?

Do I need to put rebar in deck footings?

Using Rebar for Concrete Deck Footings 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 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.

How many footings do I need for a 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. If your deck will be a different size, it’s easy to figure out how many you’ll need.

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.

Do posts need to be centered on footings?

A post bottom is embedded into concrete. The one post is not securely attached to its footing. Posts should be connected to their footings so that the posts don’t lift or slip off.

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. if you use metposts the post will still rot they just make it easier to replace & in my opinion they look horrible.

Can you pour a footing without forms?

The section on footings in Formwork for Concrete (ACI SP-4) says that when fabricated forms are omitted entirely and concrete is cast directly against the excavation, larger tolerances may apply.

Do footings have to be level?

If you’re building your wall on a slope, your footing needs to be stepped – although the concrete must always be level. The step size will depend on the slope and the material you’re using to build your wall – you should work it out in multiples of the depth of a course.

How many footings do I need for a floating deck?

For an 8×10′ freestanding deck, you’ll need six footings. Unless you have access to a power auger, that’s a lot of digging. After digging each hole, you will need to install tube forms into each. Each tube form then needs to be filled with one 60 lb.

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.

How deep should concrete footings be?

Depth of Footings Footings should extend to a minimum depth of 12 inches below previously undisturbed soil. Footings also must extend at least 12 inches below the frost line (the depth to which the ground freezes in winter) or must be frost-protected.

Which is stronger 4×4 or 2×6?

The strength is determined by the load direction. A 2×6 is stronger lying horizontally with the load applied to the 2″ edge facing up. compared to any 4″ side of the 4×4.

How far apart do deck posts need to 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 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 posts 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.

What size joists do I need for decking?

Commonly used joist sizes are 2-by-6, 2-by-8 and 2-by-10. For example, when you space joists 16″ apart — which is standard for residential decks — a deck spanning 9 1/2′ would require 2-by-6 joists, a 13′ deck would need 2-by-8 joists and a 16′ deck calls for 2-by-10 joists.

How far apart do joists need to be on a deck?

Step 4: Make Sure Your Joists Are Spaced Correctly Deck joist spacing should never exceed 16″ on center (with the exception of MAX deck boards, which allow for maximum 24″ on center). For a more rigid feel, 12″ or less may be preferred.