Though steel buildings are among the strongest and most durable building structures, they are very poor in terms of insulation. Steel is a very good conductor of heat. In hot weather steel transfers the heat of the sun into the building while in winters it transfers the heat outside. Steel buildings also face the problem of condensation.
All the above mentioned problems can be solved by proper insulation of the steel building. The problem of condensation can be solved by properly ventilating the building or by installing a vapor barrier. The insulation need of any steel building is basically decided by the location of the building and the purpose for which the building has to be used.
Insulation of a steel building also helps in deadening the sound which can be a lot useful in a building with metal walls and roof. Go for a white foil facing if you want to illuminate the interior of a building since the bright material helps in reflecting the light quite efficiently. You can use fibre glass or Icynene, a low-density, open-cell modified polyurethane to insulate your steel building as per your budget and choice.