Understanding Steel Building Foundations – Part 1
Steel building foundations are more complex than you thought!
The slab or foundation for your steel building is more complex than customers realize. The foundation of a steel building works in conjunction with the steel building to help meet the local building codes.
Have you ever stopped to think about why mobile homes are always the first victims during extreme weather events? Sure, they are lighter than a tradition home, but the big difference is that they don't have the benefit of a foundation to help them keep anchored to the ground.
A properly engineered foundation helps anchor the steel building to the ground and also helps the steel building transfer the energy of loads upon it into the foundation.
In order to accomplish this, steel building foundations have large piers under each of the columns of the steel building. Rebar and wire mesh are placed in the pier according to the engineers specifications and hairpins wrap around the pier and extend out into the center of the slab.
The details of the piers for a steel building project are determined by the engineering of the steel building and the local codes that are to be met. There is no "one-size-fits-all" pier size: while a pier in the neighborhood of 3' x 3' x 20" might be common in middle TN, a pier in south FL might be 12' x 12' x 4'.
Which comes first: the steel building engineering or the steel building foundation engineering?
Concrete costs are a substantial portion of any steel building project and it's understandable that customers want to accurately estimate this cost before committing to a project.
Here's the problem though: in order to obtain a set of stamped engineered foundation plans for your steel building project (that you will use to solicit accurate bids from concrete contractors) the foundation engineer needs to have a set of the building engineering. Without the details provided in the building engineering, the foundation engineer can not engineer a foundation.
Here's another problem: you don't get a copy of the building engineering until AFTER you purchase a building. So how do you estimate concrete costs for your steel building project?
We always recommend customers talk to an experienced concrete contractor who has experience pouring slabs for steel buildings. An experienced concrete contractor will likely be able to provide you with a rough estimate of cost per sq. ft for a finished steel building slab (including materials, labor, form, pour, finish, and anchor bolts).
Read more about metal building foundations in
Understanding Steel Building Foundations - Part 2