The two systems in a few words
In a metal warehouse, columns, beams and trusses are steel, fabricated at the plant and erected on site with bolts and welding. In precast, the members are concrete, fabricated off-site and lifted into place on site.
Both are industrialized and both arrive ready to erect. The difference lies in the weight, the span each one clears comfortably, and what happens when the project needs to grow.
Side-by-side comparison
| Criterion | Metal structure | Precast concrete |
|---|---|---|
| Large spans | Excellent | Depends |
| Industrialization | High | Medium |
| Self-weight | Lower | Higher |
| Erection speed | High | Depends |
| Future expansion | Simple | More difficult |
| Maintenance | Needs corrosion protection | Lower |
The table is a starting point. What decides is your specific case.
When precast tends to compete
- spans up to about 25 meters;
- standardized warehouses, with no expansion planned;
- projects where minimal maintenance matters more than schedule.
In these cases, it's worth putting both proposals side by side. If precast is the right fit for your case, we'll tell you.
When steel tends to win
- Large span: steel clears large distances with no column in the middle.
- Weak soil: the lighter structure eases the load on the foundation.
- Tight schedule: the pieces are fabricated while the foundation is being built.
- Project that will grow: expanding a metal structure is simpler.
Schedule: why steel is usually faster
In a metal structure, the pieces are fabricated while the foundation is being built. When the site is ready, the structure is already waiting.
Steel pieces are also lighter, which simplifies transport and lifting. In precast, the concrete pieces weigh more and call for larger cranes and more care in logistics.
Weight and foundation
A lighter structure puts less load on the foundations. On good soil, the difference matters little. On weak soil, where the foundation needs to go deeper, it can change the cost of the whole project.
Expansion in practice
A metal structure can be designed with the next module already in mind, with columns and connections ready to receive the expansion. When it's time to grow, the new part is fabricated and connected to the existing one.
Precast can also be expanded, but the new pieces need to match the old ones, and that tends to be more work.
What about maintenance?
This is the honest point against steel: a metal structure needs corrosion protection. With the right paint system for the environment, maintenance becomes periodic inspection, not renovation.
On the coast and in harsh industrial environments, this choice matters more and needs to be factored in from the design stage.
What about thermal comfort?
What most defines a warehouse's thermal comfort is the roof and the cladding, which are the largest areas exposed to the sun. Insulated roof panels and good ventilation work for both systems.
What about fire protection?
Another honest point: steel loses strength at very high temperatures. Depending on the use and size of the warehouse, fire department requirements may call for extra protection on the structure. Concrete is naturally more fire-resistant.
This doesn't rule out using steel, but it needs to be factored into the design and the cost from the start.
How to decide
Answer these questions before requesting a proposal:
- What span does the operation need?
- What is the site's soil like?
- What is the schedule to start operating?
- Will the project grow in the coming years?
- What environment is it in: inland, city, coast or industrial?
With these answers, the preliminary study shows which system makes more sense and what changes in the cost.