How to Install Window Lintels

Measure the window opening with a tape measure or get the figure from a house plan. Use a steel lintel for a window in a brick façade wall; use steel, solid stone or reinforced concrete for a stone or concrete block wall. Match the depth of the lintel to the material, such as a 4-inch 1/4-inch steel lintel for brick; the lintel must cover the full depth of the wall from sheathing to outside of the window frame.

Add 6 inches on either side to secure the lintel into the wall facade, such as a 42-inch lintel for a 30-inch window frame. Lay bricks on either side of the window up to the top of the frame. Pause and measure about six brick courses below the top of the window frame and adjust the mortar joints so the last brick on each side is flush with the top of the window frame. Do similar with stone or concrete block to provide a level base on each side.

Lay the lintel on top of the window frame. Lay the next course of brick on top of the lintel, with lintel edges extending into the mortar joints on each side. Don't put any caulk or similar material under the lintel as this may cause it to rust. Add 3/8-inch steel reinforcing bar into mortar joints in brick courses above the lintel for extra support if there will be a large area of brick above the lintel.