Steel beams have a high cost, are heavy, will rust over time and pollute the environment.
Cost
Steel beams are generally more expensive than reinforced concrete and wood beams. While steel beams cost more per lineal foot than wood beams, they also often require more labor costs because welders are needed for installation.
Rusting
Steel beams can retain moisture and condensation in a structure, while wood beams are able to absorb it. This can lead to potential problems involving rusting. Wood, in contrast, won't rust but can lead to potential termite problems.
Weight
Steel beams are much heavier than wood beams and are thus more difficult to work with. The heavy weight of steel makes the beams more challenging to maneuver than wood beams.
Appearance
Steel beams can be unattractive when left exposed. Thus, steel beams are usually hidden by architectural treatments, while wood beams can help create dynamic open areas with a rustic look.
Pollution
The production process of steel beams releases pollution into the air. It also requires a substantial amount of water in the manufacturing process, which could contribute to potential water shortages.