What is a Door Frame?
Tuesday, August 5th, 2008
Isn’t that the wood that goes around the door and holds it in place? Yes, it is the just make sure you understand a door frame or jamb is the vertical member used to secure the door either on the hinge side or the lock side. Exterior frames are intended for applications where the outside portion of the door frame is exposed to natural elements. The strength of the door frame is important because the hinges for the door are supported primarily by the frame. However, most building codes specify that at each hinge, there must be a 3” screw extending through the frame and anchoring securely in the stud wall of the opening. Most types of door fasteners and deadbolts extend into a mortise or recess in the door jamb when engaged, and the strike plate or deadbolt plate is often reinforced by wrapping it round onto the back of the frame. A good door jamb will keep a door secure and in place, without leaving excessive gaps where air can leak into the house. Weston Wood Solutions produces superior door frames. All Weston Wood Solutions’ wood door frames are manufactured using their precise specifications and materials. Exterior quality glues in all finger joints and edge laminations, and a controlled moisture content of 10-12% create a product that is strong, straight, and suitable for exposed applications once primed and painted.
There standard exterior frames include a built-in stop with a weather-strip kerf. Typically in Canada prehangers will use a compression weatherstrip on the hinge frame side and a magnetic weatherstrip on the strike frame side. For colder parts of the country we supply our door jambs with an extra groove along the rabbeted edge which is for an additional weatherstrip seal between the edge of the door and the frame. The main reason is to stop the incursion of wind, water, or snow into the structure via spaces between the door and door frame. In most parts of the US compression weatherstrip is used throughout the frame.
Weston Wood Solutions supplies frames with dados for the head jamb and the sill. These are machined to customer specifications so that the head and the sill fit snugly into the frame when it is assembled. Typically these dimensions, and the length of the head and sill, are designed to give a 1/8” gap or reveal around all the edges of the door. Most prehangers dado the top of the hinge and strike frames so that the head is recessed into the assembly. However, some prehangers prefer to dado both ends of the head instead so that there is no possibility of water migrating down into the door.
There are 2 main types of assembly techniques for double doors or entrance doors with sidelights. The most common and easiest to make, is a box system, where each component (door and sidelight) is made first and then joined or mulled together. The other is a continuous head system where the mullion fits into a recess which is mortised into the head. Weston supplies head profiles for door frames in any length, including 16 ft lineal, and a special profile called burlap which covers the joint when 2 frames have been mulled together.
It is important to ensure that the doorframes are properly primed before exterior grade paint, stain, or protectant is used to properly seal the frames from the elements.




