In the past, steel doors did not offer much by way of variety. As a result, they were not as popular as wooden doors or doors featuring other kinds of metals. The situation however, is not the same today. Steel doors come in a wide range of shapes and sizes. Both kinds of doors will typically feature cold-rolled steel or galvanised steel. These doors will be ideal for use in areas with high moisture levels. This is because in such areas, these doors will remain exposed to elements that could cause rusting. In addition, the usual core types that these doors feature will usually include:
- Honeycomb cores, for use in areas that do not require high thermal insulation
- Steel-stiffened cores ideal for use in high traffic areas (non-aesthetic applications)
- Polystyrene and polyurethane cores, which are ideal for use in cold climates and,
- Temperature rise cores, which are useful in case you need doors having a fire-resistance rating
However, several differences exist between interior and exterior steel doors. These differences typically pertain to:
- The Thickness: Interior steel doors will feature lighter gauges. In contrast, exterior doors will usually comprise heavier gauges.
- The Top Cap: Interior steel doors might not require top caps. But, exterior steel doors will require these caps to prevent the penetration of water.
- The Weep Holes: Exterior steel doors (such as horizontal bi-fold doors etc.) will usually include weep holes. These holes facilitate the escape of moisture from the bottom of the door, thereby preventing the inner section of the door from rusting. These holes will be absent in interior steel doors.
- The Insulated Core: Most interior doors will not feature any insulation. They will not have much (if at all) noise or temperature protective capabilities. Thus, they will usually be completely hollow on the inside. This is because interior doors will only serve as visual barriers between rooms. In addition, they will not face exposure to the elements. In contrast, exterior doors will need to withstand the elements.
- The External Surface: Exterior doors will usually have faces or veneers that are quite thick. Manufacturers usually refer to this feature as glazing. Doors with double or triple glazing will be able to offer protection from the rain, the snow and the ultraviolet rays of the sun. Interior doors will not include any weather-stripping features.
- The Presence of Decorative Designs: Interior doors will usually offer a decorative design on both sides of the door. These serve to make the door visually appealing. In contrast, exterior doors will typically feature decorative designs on one side only.