QA

How Deep Should Deck Posts Be

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 deep should a deck post hole be?

Dig the holes six inches deeper than the required frost line depth for your area, and slightly wider than the concrete footer tubes you’ll be using. A power auger can make this step easier and faster.

How deep should 4×4 posts be for a deck?

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).

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.

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.

Can deck posts be buried?

The buried post method offers the advantage of reducing the amount of concrete work required for each footing and actually provides additional lateral (side-to-side) support to the post to resist wind loads.

How deep should an 8 foot post be in the ground?

In general, holes should be at least 3 feet deep for posts that extend 8 feet or more above ground level. Posts that extend 6 feet above ground level should have holes at least 2 1/2 feet deep.

Can you put dry concrete in a post hole?

Fast-setting concrete is ideal for setting posts because there’s no mixing—you simply pour the dry concrete from the bag right into the hole, then add water.

Can pressure treated posts be set in concrete?

Simply setting the posts in concrete does create a condition that will accelerate rot in the bottom of the posts. With pressure-treated posts, the rot will be slow. Concrete should be poured around the post – no concrete under the post.

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 use 4×4 posts for a deck?

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 you notch deck posts?

Say “No” to notching pressure-treated deck posts. We want you to build an outdoor railing system that you, your family and guests can enjoy without worrying about safety issues. In order to do so, you need to know this building shortcut is not advisable, and we recommend avoiding it at all costs.

How much load can a 4×4 post support?

4×4 can hold up to 4,000 pounds when laying horizontally with the right support. Vertically, a 4×4 should support 4300 pounds but can hold significantly more. The amount of weight that a 4×4 can hold depends on several factors like wood grade, species, and load type.

Is a 4×4 post stronger than 2 2x4s?

When used vertically, 4x4s are stronger than two 2x4s. However, if you need a horizontal surface, two 2x4s will be stronger than one 4×4. A 4×4 should not be used horizontally for anything structural. Always be sure that you’re using the proper size and strength of lumber.

How long will a treated post last in the ground?

A treated 4×4 will last 20 to 25 years in the ground if the conditions in the soil and climate are favorable. That number could increase to 40 to 75 years if you install the treated 4×4 in a cement ring rather than the soil. There are a few factors that influence how long the 4×4 can last in the ground.

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

Backfilling the fence post hole with gravel is another common alternative to using cement. Start with a hole about the size of the one you’d dig if you were using cement, insert a third of the post’s length into the hole, and then fill with crushed gravel, tamping every five inches until flush.

How do you build a deck without burying posts?

If you’re ready to start planning, there are two great options to build a deck without digging any holes: surface deck blocks and deck foot anchors. The cheapest foundations are deck blocks, which can be purchased for less than $12.00 a piece. Deck blocks sit on the ground, so proper planning is essential.