Door Frames—Defining the Opening

Once a door opening is designed into a space and located in a wall, that opening needs to be framed in some manner to serve several purposes. First, the frame closes off and trims the wall construction. Second, the door frame supports the door itself and provides the means for assuring a plumb and level condition. And in cases where it is needed, the door frame contributes to the integrity of a fire rating. Beyond providing these basic functions, however, there are actually many choices of door frames available to work with many different design conditions.

Hollow Metal Frames

Hollow metal frames are the default door frame for many commercial and institutional building designs. They are proven, durable, economical, and suitable for a wide variety of settings. Beyond that, hollow metal door frame profiles are available in a wide variety of shapes and sizes that can make them less visible or more prominent to suit an overall design scheme. This means that beginning with the wall opening itself, the visual framed appearance of that opening can be controlled in terms of how much or how little of the frame to make visible and in terms of what three-dimensional form that frame takes.

Door frames are not limited to just a standard 2-inch flat face. A wide variety of prominent or subtle profiles are available to suit different design aesthetics. Images courtesy of ASSA ABLOY

In some cases doors and frames are part of a wall that is performing a thermal separation as between indoors and outdoors or between two rooms that have very different normal operating temperatures. In that case, energy-efficient hollow metal frames are the most appropriate to use. There are two common types:

Thermally broken frames are fabricated to interrupt direct heat transfer through the metal frame by fabricating them in two parts with a less conductive material in between. They work the same way that thermal breaks in metal windows work and in that regard they are suitable to reduce heat loss anywhere that thermally broken windows are used. These door frames are ideal for openings directly exposed to cold or hot temperature differences between the two sides. In the case of exposure to cold, they can be an effective deterrent to frost and condensation that might otherwise form on the metal frame.

Kerf frames are not typically thermally broken, but they do address another concern—air sealing the door using weather-stripping. Now, in reality, most door frames can receive weather stripping; it's just that a kerf frame makes it easier by virtue of an integral groove manufactured into the profile of the entire frame. This groove means that the installation of the weather stripping is simplified and that no additional fasteners are required to hold it in place.