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Steel Buildings Versus Tilt-up and Concrete |
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When Does Concrete and Tilt-up Make More Sense Than Steel
Buildings?There are several factors that may make other
methods of construction, most notably tilt-up construction, a better choice than
steel buildings. The most obvious factor is the building's
size. For projects less than 50,000 square feet, steel is generally the least
expensive alternative. For a building of this size, the fixed or "open the
door" costs of a tilt-up construction project (like the rental of a large
crane, for example) make it more expensive than steel, even though concrete is
usually a less expensive raw material. As projects become larger than 50,000 square
feet, however, the lower price of concrete starts to offset tilt-up construction's
fixed costs and this method becomes cost-competitive with a metal building. The
larger the building, the more advantageous tilt-up construction becomes.
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| The
moble crane lifts the panel and tilts it into position over the footing on this
tilt-up construction project in the Dallas / Ft. Worth, TX area. In many cases,
tilt-up construction is a better - and even more economical - choice than steel
buildings. |
| The cost of the steel building kit
will usually be lower than a price quoted for a concrete building, even a tilt-up
building. If customizing or modifications to the kit are necessary to meet the
owner's needs, these design costs must be included when comparing the prices.
Also, the kit price may not include costs that are normally incorporated into
a quote for a tilt-up or traditionally constructed building. Some of those costs
include concrete foundation, permits, erection and assembly costs, taxes, electrical
wiring, plumbing, environmental controls, ductwork, interior finishing, etc. The
location of the project will also influence whether a steel building is even an
option. Builders in agricultural or lightly populated areas generally have fewer
code restrictions placed on them. The closer a building is planned to a densely
populated area, the more stringent the fire codes, building permitting requirements
and other municipal standards become. In some cases steel buildings can not be
used in certain areas for this reason. Other times, fire codes may require steel
buildings to be built further apart than tilt-up structures, requiring a larger
plot of land for the project. This is why, in urban areas, buildings closer to
the downtown area are generally made of concrete and steel buildings become more
common on the outskirts of town. The reason steel buildings
face greater code limitations is that they generally offer less fire protection
than tilt-up or other concrete buildings. While steel is not combustible, it is
not considered fireproof because it can distort or lose its structural strength
when exposed to heat. Further, a fire on one side of a metal wall can generate
destructive heat on the other side, damaging the property inside. Steel building
designers use a variety of technologies, from sprays to fire-retardant panels
or blankets, to mitigate the fire-resistive problem. By comparison, a typical
6.5" concrete wall has a fire resistive rating of four hours or more. Tilt-up
and concrete provide superior fire protection for the property and people inside
a building. The intended use for a building will also influence
whether steel or concrete is the best choice. In general steel buildings work
very well for storage buildings, indoor sports facilities, work shops, and aircraft
hangers, but they are less suited for higher-trafficked buildings. Comparatively
speaking, steel walls are less durable than concrete walls. This holds true in
the face of natural forces (bad weather, earthquakes) as well as for truck or
forklift accidents. When a building is damaged by a vehicle, the damage is generally
more localized and less expensive to repair for a tilt-up or concrete building
than for a steel building. For owners who want to build a warehouse or other facility
where trucks or forklifts will be used, this can be a very important consideration.
Defense contractor facilities, prisons, or other buildings that require positive
security also are much better suited to impenetrable concrete than to comparatively
insecure steel. While steel is reasonably durable, concrete
remains the material of choice for buildings that require less upkeep and maintenance
over the years. Concrete is impervious to corrosion, rotting, rust or insect infestation;
tilt-up buildings created in the 1940s are still standing today with little apparent
wear. The fact that builders in earthquake-prone California now use tilt-up construction
for 90% of their single-story commercial projects indicates that concrete buildings
are cost-competitive and extremely durable. When factoring
in potential repairs and ongoing maintenance, it's apparent that the real dollar
difference between operating a steel building and a concrete building can be significant.
Further, the added fire safety and durability of a concrete building will usually
be reflected in lower insurance premiums. If the owner decides to sell the property,
they will most likely find that a tilt-up or other concrete building depreciates
less and than a steel building will. Return
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