Asked by: Zahira Hinterkopf
business and finance civil engineering industry

How far should a deck post be in the ground?

Last Updated: 10th April, 2020

26
8 feet

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Hereof, how deep do post holes need to be for a deck?

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 2x4 or wood post.

Beside above, 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. When concrete is poured around a deck post in this way, the post will rot due to moisture buildup by the soil.

Likewise, should deck posts be in the ground?

There are several ways to set deck posts; we recommend attaching the posts to concrete footers above the ground. This helps to prevent wooden posts from rotting. Set footers a minimum of 6” below the frost line for your area to prevent movement during freezing temperatures.

Can you use 4x4 posts for a deck?

In the past, many decks were built with 4x4 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.

Related Question Answers

Xueqin Mendiaras

Professional

Can pressure treated posts be set in concrete?

With pressure-treated posts, the rot will be slow. First, the posts should be set on top of a bed of coarse gravel 3 to 6 inches deep, so the base of the post is in contact with the gravel. Concrete should be poured around the post - no concrete under the post.

Urbano Kalashnikov

Professional

Can deck posts be buried?

The Buried Post Footing. This footing method involves pouring a concrete pad at least 12” thick at the base of your hole. The pressure treatment companies insist that these posts will last longer in the ground than the deck frame that is built above it, and this practice is accepted by the IRC code.

Ceila Didrikil

Explainer

How many bags of concrete do I need for a deck of footings?

60 cubic feet when combined with 4 quarts of water. If you're purchasing 80-lb bags of concrete, you'll need 1.66 bags of concrete. As before, since bags of concrete are only sold in whole quantities, you'll need to purchase two (2) 60-lb. bags of concrete to form one cubic yard.

Edris Vohrer

Explainer

How many support 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.

Kalsoom Adaixo

Pundit

How do you build a deck without digging holes?

Precast piers make it unnecessary to dig holes for your deck.
  1. Set your precast deck piers in a grid, at roughly three- to four-foot intervals.
  2. Measure your grid diagonally from corner to corner, using a measuring tape.
  3. Extend the line level to determine if the piers are level as a helper holds the other end.

Aiyong Landaco

Pundit

What size footings do I need for a deck?

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).

Abencio Wienandt

Pundit

Should deck footings be above grade?

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.

Nazmie Heddrich

Pundit

How do you reinforce a deck post?

Reinforce post connections
Strengthen post connections with carriage bolts. Drill holes, knock the bolts through, then tighten a washer and nut on the other side. Ideally, posts should sit directly under the beam or rim joist to support the deck.

Inoa Gritti

Teacher

How do you build a deck step by step?

ready mix concrete
  1. Step 1: Ground-Level Deck: Dig Holes for Posts.
  2. Step 2: Pour Concrete and Place Post Anchors.
  3. Step 3: Attach Beams to Post Anchors.
  4. Step 4: Attach Rim Joists and Angle Brackets.
  5. Step 5: Attach Inner Joists to Beam Faces.
  6. Step 6: Install Boards and Add Fasteners to Joists.

Antenor Urquiza

Teacher

How do you anchor a deck to concrete?

How to Attach Deck Post Bases to Concrete Footers
  1. Hold your drill plumb. Use a drill with a hammer drill bit to install a concrete sleeve anchor into the center of the concrete footing.
  2. Don't over tighten the bolt. Install the Adjustable Post Base to the sleeve anchor and tighten the bolt to secure the attachment.
  3. Place your foot behind the post when nailing.

Fodil Invitto

Reviewer

How do you set a 4x4 post on concrete?

Project Instructions
  1. 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).
  2. Add about 6 inches of QUIKRETE All-Purpose Gravel into the bottom of the hole.
  3. Set the post into the hole and attach 2x4 braces to adjacent sides of the post.

Abderahim Pender (2)

Reviewer

How do I put a post in the ground without concrete?

Procedure:
  1. Find a concrete surface and lightly tamp your digging iron against it.
  2. Remove the turf and topsoil from the site of the post.
  3. Dig the hole putting the displaced earth onto the tarp.
  4. Pour 4 inches of gravel into the hole.
  5. Place the post in the hole.
  6. Add another 2 inches of gravel around the base of the post.

Letisha Roscoe

Reviewer

Is 2 feet deep enough for fence posts?

The minimum depth that you should dig your fence post holes for panel sections is 2 feet. A general formula is to dig the holes one-third to one-half of the post's aboveground height. The deeper you dig the holes, the more stability your fence has, but you must also purchase longer posts.

Josiane Alunni

Reviewer

How do you build a ground level deck on uneven ground?

How to Build an Elevated Deck on Uneven Ground
  1. The finished deck before painting and sealing.
  2. The Setting of the Poles Will Make or Break This Project.
  3. Don't Do More Work Than You Have To.
  4. The frame with joists and struts.
  5. Bolts connect front and back frame and posts.
  6. Set post supporting frame.
  7. Use a level for every connection.
  8. Clips used for extra support on joists.

Castulo Mombers

Supporter

Can I use deck pier blocks instead of footings?

Concrete Pier Blocks for Decks. A deck pier block is in many ways just a simplified version of a “precast foundation”, a foundation type recognized by building codes. They're subject to all of the same requirements as a typical footing, regardless of not being cast-in-place.

Abdrahamane Danilyuk

Supporter

Can I pour concrete around deck posts?

In weak soils you want to reduce the loading on the soil. A larger cross sectional area post will do that. Pouring concrete around the post, as long as the concrete is locked onto the post, will do the same.

Dauda Schmidbauer

Beginner

Should posts be set in concrete?

Setting Fence Posts in Concrete
Concrete is the most secure material for setting fence posts, especially if you have sandy soil. Gravel may be okay with dense, clay-heavy soil, but in looser soil, concrete is the only thing that will truly keep your fence posts stuck in place.

Nareme Vigoda

Beginner

Can deck blocks be buried?

In most regions of the country, that means securing support posts to the foundation with code-approved metal connectors, or having the ends of posts set on concrete deck blocks buried at least 12 inches below grade (the top of the soil).