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  • Writer's pictureDuncan Farrow

5 Foundation Types for Post Frame Buildings

When you build a post-frame building, like a big barn or workshop, the foundation is super important. It's like the legs on a table - it keeps everything standing up straight and strong. We're going to talk about five foundation types for post frame buildings, each with its own pros and cons.

wood in ground pole barn foundation

Wood Posts in the Ground: The Simple Way The old-school way to make a foundation for a post-frame building is to put wood posts right into the ground. It's a popular choice because it doesn't cost much and it's pretty easy to do. You don't need to use a lot of concrete or other expensive stuff.

But there's a downside. Wood doesn't last forever when it's stuck in the ground. It can rot after 25 to 40 years, which means you might have to replace it down the road.


  • Cost-effective and labor-saving

  • Reduces the need for concrete or other materials


  • Susceptible to rot with a typical lifespan of 25 to 40 years

  • Longevity heavily dependent on soil conditions

Perma Column foundation

PERMA Columns: Strong but Can Sink PERMA columns are like upgraded wood posts. They're made of concrete, so they don't rot like wood does. They're a bit more expensive than just wood, but they're not the priciest option out there.

The problem with PERMA columns is that they can sometimes sink into the ground a bit, especially if the ground isn't super solid. So, they're strong, but you have to make sure they're put in right.


  • Durable

  • Moderately priced, offering a middle-ground solution


  • Potential for settling, which can lead to unevenness

  • Base preparation and soil type can influence stability

cast in place concrete piling foundation for a pole barn

Concrete Pilings Poured on the Spot: Made to Fit Another way to make a foundation is by pouring concrete pilings right where your building is going to be. This means the foundation is made to fit exactly in your building spot.

These are great because they don't rot and they usually don't sink. They do cost a bit more than PERMA columns because there's more work to do when you pour the concrete right there.


  • Excellent durability.

  • Reduced chance of settling due to the integrated footing base


  • Higher cost compared to PERMA columns

  • More labor-intensive with the need for on-site pouring

screw pile foundation diagram

Screw Pile Foundations: No Sinking Here Screw pile foundations are really strong and they're made to last a hundred years! They don't rot or rust, and they don't sink because they're screwed into the ground.

They're more expensive than the other types we've talked about, but they're a good choice if you want something that's going to stay put and not move around.


  • Long lifespan of approximately 100 years

  • Engineered to prevent settling and provide strong uplift protection


  • Higher initial investment

  • Requires precise installation to achieve the necessary torque

foundation wall for a custom shop

Traditional Foundation Walls: The Top Choice for Slopes If your building site is on a hill or slope, you might want to use traditional foundation walls. They work as both the foundation for your building and a retaining wall to hold back the dirt on the slope.

These walls are the most expensive choice, but they're really good at what they do. They won't sink, and they make a strong side for your building that's great for when you need to clean out the inside with machines.


  • Ideal for sloped sites, doubling as retaining walls

  • No settling issues and offers a robust barrier for interior operations


  • The most expensive option among the five

  • May be over-engineered for sites without slopes or specific interior needs

Picking the foundation for your post-frame building is a big deal. You've got to think about how much you want to spend, how long you want it to last, and what your building site is like. Whether you go with the simple wood posts or the upgraded foundation walls, make sure it's the right fit for your project. That way, your building will stay up for a long time.

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