Stability is paramount for any building, and steel structures are no exception. That means using the best foundations for the conditions, and there are options.
Slab foundations are the most common. They involve a huge concrete slab with deeper, reinforced concrete footings, often with a thickened perimeter, that extend below the local frost line to prevent movement.
Pier foundations are deeper, with cylindrical columns (piers) that reach down to stable soil or bedrock so that the weight is put on this, rather than the less solid earth closer to the surface. Pier foundations are often used for bridges and very tall buildings where the upper soil layers are relatively soft.
A perimeter foundation is a continuous structural wall that outlines the exterior of a building. It elevates the structure above the ground, creating a usable crawl space or basement underneath the building.
The best type of foundation will be decided by the constructor, and Atlantic Steel Structures will explain the choice, just as we will any other aspect of the construction of your steel building.
Why Your Foundation is Just as Important as Your Steel
Steel structures are distinctive and are always referred to as steel buildings, because clearly the choice of material is crucial and offers advantages that other materials do not. It is vitally important to choose the best type of steel for the job. We will talk you through this, pointing out the qualities of carbon steel as opposed to high-strength low-alloy steel and weathering steel, each of which has particular strengths.
It is equally important to get the foundations right, and the sheer weight of experience within Atlantic Steel Structures gives us the know-how to go for one style over the others.
Concrete Slab Foundations: The Most Popular Choice
Slab foundations are in many ways the obvious choice, and certainly the most common. They are relatively simple to create and offer excellent stability along with short construction timelines, improved energy efficiency, and a reduced risk of pest infestations or moisture buildup because they do not have hollow areas like crawlspaces or basements.
Pier Foundations: Ideal for Agricultural and Uneven Sites
Construction sites may all look alike to the layperson – just an area of cleared, slightly excavated earth – but there can be more to them than meets the eye. If, for instance, the land is naturally uneven or has been used for agricultural buildings and is therefore relatively soft, the deep reach of pier foundations may be the ideal choice.
Perimeter/Stem Wall Foundations: When and Why
Uneven or sloped sites present challenges for construction which can be solved by the use of perimeter/stem wall foundations. Because they involve a solid, concrete crawlspace beneath the building, they offer the opportunity to put plumbing, electrical cables, or HVAC (heating, ventilation, and air conditioning) units there, safely out of the way but accessible.
How Soil Type, Climate, and Building Use Drive the Decision
Soil type is an obvious factor when selecting a foundation type, because there are huge differences between soft, absorbent soils and grittier ones. The basic requirement is that the building is not going to sink as the soil subsides.
Climate is also important, because in very cold areas, for instance, frost can go deep and the foundations need to get beyond that for stability. Areas with high rainfall present obvious issues which must be considered, and the foundations must be either protected by drainage or deep enough to be anchored in the stable levels further down.
The weight of the building once it is loaded with whatever is involved in its function presents a further consideration. The building itself is one thing, but if it is used for storage of heavy materials, that weight can increase dramatically. Similarly, if what is going to be happening in there will produce a lot of vibration or concentrations of weight (people, animals, etc.) moving around the building, that can influence the choice of foundations.
Ballpark Costs for Each Foundation Type
Let’s assume the preparation has been done, the land cleared and ready for foundation work to begin, as these costs will be much the same for any kind of foundation.
For concrete slab foundations, you’re looking at between $6 and $14 per square foot. Pier foundations should come in at around the same level.
The perimeter/stem wall option is more expensive at roughly $15-$30 per square foot.
These costs are approximate as of mid-2026. For a more definite figure, reach out to our team for a free quote here.
