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Should You Set Deck Posts In Concrete? [And How To]

Before placing a deck post, your major concern may be where to place it, so it is secured better. Should you set it on grass, gravel, or concrete? We have consulted hardscaping experts to give you adequate information on everything you need to know. 

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Yes, you can set the deck post on concrete, but it should be on concrete footers higher than the ground level. This would enable the wooden material of your posts to last longer without rotting. Setting it on concrete footers would also keep it safe during harsh seasons like winter. 

Deck blocks can also be alternatives to concrete. They are also safe and long-lasting. To know more about deck posts, keep reading as we will explain further down this post. 

Luxury home with illuminated windows and a large composite deck in the woods, Should You Set Deck Posts In Concrete? [And How To]

What Are Deck Posts?

A deck is an outdoor floor supported by a frame, posts, and footings set into the ground. A deck is constructed entirely from the ground up.

Standing on a deck may make them appear simple to construct, but every deck build involves several crucial elements. Decks must be carefully built to ensure they are secure and safe because they are intended to bear weight and endure for a long time.

Big house with walkout deck in brown and white trim

Should You Set Deck Posts In Concrete?

Although concrete can appear to be one of the most lasting building materials, it might not be a very sturdy material for setting your deck. Concrete has a propensity to absorb moisture, so the wood it is anchored to will quickly begin to rot and shatter.

The entire framework of your decking will be put at risk if your struts begin to decay. You can be sure that your decking will have major problems when you put weight on it if it is mounted more than one story up. 

Showing support frame and gravel under porch

It can seem smart to place the deck posts in concrete to increase their strength. The deck is kept from swaying in the wind or blown over by the concrete and earth holding the post erect. However, the increased post rot might hinder this. 

Since deck blocks won't expand as much under pressure as concrete will, they are a considerably safer alternative to concrete. Instead, a metal footing serves to divide the concrete from the wood. A concrete casing would not be as stable as this metal footing, which will prevent any water from reaching your wooden post.

Check out this metal footing on Amazon.

How to Set Deck Posts On Concrete

Construction worker screwing down wood deck with battery power screw gun or drill

Although you generally need more than one person to set up a decking anchor, they are very simple to set up. Before the posts are inserted into the indentation, they must all be lined up.

You must first check that your decking anchors are placed evenly apart and in line with each post. It might require some planning to accomplish this. As a rule, there are around 6 feet between each pillar to ensure that the weight is evenly distributed throughout the decking.

Use a jackhammer to drive the anchor into the ground lightly. Throughout the entire process, you should ensure that everything is level. Your decking could become dangerously imbalanced if one of its posts is unequal, which could happen in the future.

The fact that these decking anchors don't have an additional cross-section is another benefit. This implies that you can set up and install your decking quickly without needing additional tools or concrete pouring.

You can create higher decks using these deck blocks; some homeowners choose to raise their decks to eight feet high. 

Check out this jackhammer on Amazon.

Should Pressure Treated Post to be Set In Concrete?

You can assemble pressure-treated wood right on top of concrete. To begin with, make sure the concrete surface you are working on is level and smooth. The surfaces should be smoothed with sandpaper, and any holes and cracks should be filled with cement.

The pressure-treated wood boards can now be nailed to the concrete once the surface has been prepped. A type of wood known as pressure-treated wood has undergone a particular process to make it resistant to rot, mildew, and other types of wear and tear.

You can ensure that your pressure-treated wood deck is sturdy by picking the right wood and adhering to the recommended installation procedures. It is important to remember that not all applications call for pressure-treated wood.

It might not be appropriate for producing smaller objects like furniture. So, before utilizing pressure-treated wood in your project, always verify the manufacturer's instructions.

However, pressure-treated wood is a great choice if you want inherently resilient wood for your patio or deck. Ensure you wear the appropriate safety equipment when working with pressure-treated wood.

What Should I Put Between Wood And Concrete? 

The wood needs to be pressure treated anywhere it will come into contact with concrete or the ground. A gasket or strip of closed-cell foam can be put between the concrete base and the sill plate for added moisture protection.

Closed cell pe foam

The most common types of acceptable lumber are pressure-treated wood and naturally resilient wood, also known as the heartwood of redwood, cedar, black locust, and black walnut. Sometimes, separate the wood from concrete using a vapor retarder or water-impervious membrane.

How Do I Keep My Post Level While Concrete Dries? 

Setting the posts for your deck needs conscious effort, but it may also be exhilarating. The ends of deck posts must initially be square because they must be plumb.

Each post should be quickly squared at the bottom and cut if necessary. Before placing the chopped ends in the anchors, cover them with a preservative or concrete and let them soak for the night.

If you're building a deck, you'll have to have a steady post. To start, square out your layers with strings and mark your post locations. Turn to use a post hole digger or auger to dig out the areas you have marked for your posthole. 

Use gravel and surround the base with concrete. The deck post hole will have to be dug deeper. Fill the bottom of the hole with concrete, place the post, and pour in the concrete. Use a post level for every post to ensure it is straight and firm. Attach braces to make sure the post is in a firm position.

Add water to the concrete according to the manufacturer's direction At about twenty to forty minutes, the concrete should be set. If you have assistance, setting the deck posts will go more than twice as quickly. Better still, have two helpers so you can modify them without moving from one post to another.

How Long Will A Wooden Post Last In Concrete? 

For exterior uses, pressure-treated wood and concrete are two popular building materials. Setting the wood in concrete, though, could hasten the rotting process. Pressure-treated wood will rot in concrete when exposed to moist conditions, such as trapped water.

In ideal circumstances, pressure-treated wood buried in the ground may last for 40 years. Pressure-treated wood, on the other hand, might only last a few years when positioned vertically in a non-draining concrete base.

How Wood Rots In Concrete

The treated wood would eventually decay despite being pressure-treated with a chromium, copper, and arsenic solution. Only the rotting process is stopped and slowed down by pressure treatment. No matter how it is treated, wood will absorb moisture.

The moisture will spread throughout the wood like hot wax on a wick. And the additional moisture may cause the wood to swell. The moisture that permeates the wood will keep doing so into the hollow where the implanted piece of wood is.

As a result of the moisture being retained inside the concrete, the rotting of the wood is expedited. Imagine it as a cup that contains water. Concrete does allow some water to pass through, but not nearly enough for the impact to be considered drainage.

How Do I Make Sure My Post Is Level?

Carpenter checking level of deck boards

Put a T-bevel at the appropriate height on the first post. The T-bevel guarantees a level line and measurement. Mark the required height on the post by drawing a pencil line across it.

Cut over the drawn line using a circular saw to shorten the post and make a level top. To ensure the cut's plane is leveled, keep the saw steady while you cut. Discard the post's cut-off end.

Make sure your 2-by-4 is long enough to reach between the posts by measuring the space between them. To ensure the fence's stability, fence posts should typically not be spaced further apart than 8 feet. Cross the newly cut post and the following in line with the 2-by-4.

To check whether the posts are level with one another, use a 4-foot level in the middle of the 2-by-4. Until the level is balanced, raise or lower the 2-by-4's end. Make a pencil mark in this location on the fence post. Using the T-bevel, trace a straight, level line across the post.

To Wrap Up

Decks are floors made up of wood. To ensure that your decks are firmly placed into the ground, you can use concrete or deck blocks to secure them. Decks are made of wood, and they are likely to get rotten in the concrete because concrete absorbs moisture. 

For more articles about decks, check out these related posts: 

Can You Sand a Deck After It Rains?

What Color Should I Paint My Deck?