There are different foundation or support types to choose from when constructing a house, building, or deck. If you have chosen to work with concrete pier blocks but don’t know how to use them, you're on the right page! We have researched available information for you, and this is what we found.
You can use concrete pier blocks that have a metal bracket with decks, floors, sheds, and walkways, depending on which of the metal brackets below is attached to the block:
- Porch post base
- U-shaped post saddle
- Adjustable post base
- Adjustable post base/saddles with wind-uplift
In this post, we'll discuss these metal brackets and what you need to know about how they function. Keep reading as we cover them in greater detail below.
Using Concrete Pier Blocks With Metal Brackets
As a conventionalized precast foundation recognized by building codes, a concrete pier block is subject to all requirements like a typical footing despite being pre-formed. The blocks serve to evenly distribute the weight at the bottom of a structure on firm soil and to brace beams for support.
These precast blocks are often used in building decks. You have to bury them at least 12 inches below frost level on stable ground or place them directly on top of the soil. Whichever bracket type they come with, these concrete pier blocks must be positioned correctly and have an adequate bearing area.
We discuss the different brackets that may be attached to the blocks below.
Porch Post Base
A concrete pier block with a porch post base is commonly used to support permanent porch framing throughout the construction stage. The deck should be framed first to get the most accuracy.
When positioning a post for the porch, just put it on top of the porch post base and secure it with bolts. This metal bracket also has an inch of a standoff that reduces the decay of the post or column.
Click here to see this porch post base on Amazon.
If there is a roof over the deck, additional uplift loads must be accounted for. The load will be transferred to the post, down to the deck's frame, and in the concrete pier. The metal porch post base offers more uplift capacity than the other metal brackets.
Check out the video below to see how concrete piers with porch post bases are used in building a deck:
U-Shaped Post Saddles
This type of metal bracket has a design that connects wood posts to the footing. The U-shaped post saddle is intended specifically for post-installed applications. It can also support bases of fences, gazebos, or pergolas.
The unique U-shaped design keeps the post raised off the ground, which can protect it from rotting and corrosion. The thickness of this metal ensures structural stability as well as style.
The post on the metal bracket will solidly fix the square post to the concrete base. It is used mostly for a 4 x 4-inch square post, but it is likewise available to fit 6 x 6-inch posts.
Click here to see this U-shaped post saddle on Amazon.
Adjustable Post Base
This standoff base provides a strong connection to concrete. The beam in this type of metal bracket can be placed horizontally.
Click here to see this adjustable post base on Amazon.
The adjustable post base keeps the lumber one inch off the ground, so there is no moisture contact when the weather is wet or rainy. The bracket also has an increased uplift load for wind loading or even an earthquake.
Watch this video below to learn more about pier blocks with an adjustable post base:
Adjustable Post Base With Wind Uplift
The adjustable post base with wind uplift provides a connection between the deck posts, its vertical columns, and a concrete footing. It helps resists download, uplift, and lateral loads. This post base has an upturned leg with three sides.
To set the post or beam in this metal bracket, you slide the post in, turn the last leg up, and secure it with dry fasteners.
The adjustable post base has a one-inch standoff that drains away water build-up and dries water quickly. It also keeps the beam in direct contact with the concrete.
Click here to see this post base with wind uplift on Amazon.
Pros & Cons Of Working With Concrete Pier Blocks
When building a new deck, porch, or shed, you need to think first about the foundation and supports that you will use. In considering these things, you must consult your local building codes for some rules and regulations.
Here are the pros and cons of using concrete pier blocks in case you decide to use this type of foundation or support:
- Concrete pier blocks are cheap.
- They are easy to install.
- They do not decay.
- One person can deal with them.
- There is no mixing of concrete on site.
- They can be of different shapes and sizes.
- Concrete pier blocks are sometimes unstable when placed on soft and wet ground.
- Manufacturing faults might be present.
- There can be damage from transportation.
- They cannot be attached to permanent structures with frost protection.
How Much Weight Can A Pier Block Support?
Since the purpose of a concrete pier block is to distribute the weight of the structure on top of it, you need to determine how much weight the block can bear. An average pier block can support 1,700 PSI (pounds per square inch) to 1,900 PSI.
How Many Pier Blocks Do You Need?
The number of pier blocks you'll need depends on the soil condition, layout, size, and weight of the structure you will build. Softer soil requires more weight distribution since the ground cannot handle much weight. As a result, you'll need more pier blocks. It is also the same if there are heavier structures.
In general, lighter structures demand support every three to four inches. A standard 12 x 12 shed may require an average of 18 blocks. Drawing and calculating the variables considered will greatly help you in determining the number of blocks you will use.
Will Pier Blocks Sink?
Concrete pier blocks are typically in direct contact with the ground. That is why the soil must be compacted and strong.
If the soil is soft or loose, it can cause erosion, and the blocks may sink. Additionally, if the weight is not evenly distributed, the block receiving too much weight will likely sink. As a result, more blocks are recommended in soft, wet soil.
Difference Between Concrete Pier Blocks And Concrete Footings
When choosing a foundation, you need to consider the type of structure you'll build. Concrete pier blocks and concrete footings are two different foundations that can be relied upon. A concrete footing is made on the construction site, while pier blocks are precast foundations or ready-made.
Concerning installation and cost, pier blocks are cheaper and easier to install than concrete footings. As we already mentioned, pier blocks are suitable only for certain structures like decks, sheds, walkways, and porches and in areas where frost is not a problem.
Concrete footings, on the other hand, are best used for permanent structures because they can handle more weight than a pier block. Concrete footings are also the primary choice in places with high frost levels since they can endure the constant alterations in construction materials when seasons change.
Check out "Deck Blocks Vs. Concrete Footings" to learn the difference between these two materials and how and where they're used.
Knowing how to use precast foundations such as concrete pier blocks with metal brackets is vital for a building project. Your structure depends on these materials, and they can impact its lifespan. You don’t want to make hasty decisions and choose materials based on ease of use and cost of construction.
Choosing what materials to use and learning how to work with them is a must. You can’t go with the trend and not take into consideration underlying external and internal factors, because at the end of the day, your safety and convenience will be put at risk.
Before you leave, make sure to check out these other posts:
How To Use Concrete Deck Blocks [A Detailed Guide]
Should You Set Deck Posts In Concrete? [And How To]