Main Index

Windows and Doors

Operating Problems

Problem: Difficulty in operating a door or window.

Cause: Deflection or rotation of lintel.

Windows and doors are not designed to support vertical loads form other elements of the wall system.


  • Avoid eccentric loads on lintels. Ensure adequate lintel strength and full bearing on jack studs. Make sure that jack studs are square. Limit lintel deflection to 1/360 of the span.

As an example, for a 6 feet (1.8 m) opening the lintel deflection should be less than 1/4 inch (5 mm).

  • Avoid using shims between the frame head and lintel to prevent loads from being transferred to the frame of the window or door. Shims should be used only at the frame jambs and sill. Any anchoring at the head should be with flexible straps to allow some spring action as shown in Figure 22.

Window Shim Positions

Figure 22 - Window Shim Positions

  • Avoid nailing through the brick-mould into the lintel.