Fiberglass Door Frames and Jambs

Every Door Needs A Frame

Doors aren't affixed directly into brick or wood or whatever material makes up the house. The bolt of the lock of a door also doesn't extend directly into brick or wood. Every door hangs on hinges that in turn are attached to a frame. What is a jamb? The jamb is the technical word for "frame", and consists of the two sides plus a top or head.

Frames can be made of fiberglass too, even if the door itself is made of wood or some other material. Because most wood doors and even metal doors have shorter life spans than fiberglass, it makes sense to some to install a durable fiberglass frame into the door of another material may be hung. Doing so ensures reduced replacement and repair costs for at least the frame.

The jamb is the technical word for the frame that houses the slab of the door (or what we typically just call the door). It is also the interface between the wall and the door. Before installing a new one, the old one needs to be removed. This is not an easy task but we found a video for you that goes through the rough steps needed for an interior door.

The frame is essentially a very long, U-shaped bracket that clamps to the wall on one face and is anchored down with screws. The other face of the frame holds the hinges and mortise housing (for the lock). Installation requires proper orientation for handedness of opening. A right handed opening is opposite from a left handed one. Consult with a builder's manual to understand which is which. This video shows the installation of a "flat jamb" with a prehung slab.

Installation of the frame is not an easy process. The frame is liable to twist as it's being installed, which means that ensuring it's square and plumb is vital. If the installer forces the structure with too much force into the raw opening, there can be bowing or twisting. Problems with warpage of fiberglass entry doors are sometimes traced to problems in installation at this stage. Unfortunately, no matter what kind of door goes in later, the initial misalignment means that the finished product will be also twisted.