Fire

Setting objects on fire can be tricky, especially when they can't cause harm to the building or when the sets must be able to be used for multiple days of filming. To cause a building to be on fire without actually burning it boxes are constructed behind the windows and used to contain smoke, flames and flares. From the outside it appears as if there is raging fire withing the building.

Differing types of flame bars are used to create fire effects. These are metal tubes with holes in a variety of places to allow the gas pumped into them to escape and be ignited. Propane gas is used for interior scenes and diesel for outdoor.

Another option for lighting a set on fire is to spread a highly inflammable gel on the objects, which lasts for a limited period of time.

Sets that must be caught on fire are mainly built with fireproof materials so as to ensure that only the gel or the gas use is what is burning. This also preserves the sets so they may be used across multiple days of filming.