Sagging Lintel Repair


A lintel is defined as a horizontal support of timber, stone, concrete, or steel across the top of a window or door which supports the weight above the opening.

In masonry work, a lintel is a support form that is left in place to ensure proper stability for both brick and mortar. Because masonry goes together wet and cures to a hardened state after 28 days, it is impossible to install masonry over a door or window without using a masonry support during the curing process. While a lintel can be made from timber, stone, or concrete, it’s almost always made of steel when used in masonry. Steel lintels can be flat bars which are either used flat or bent into other shapes, such as an arc when used under a brick archway; however, most steel lintels used in masonry are what are known as angle iron lintels.

An angle iron lintel is a piece of steel lintel that is bent at a right angle to provide support. They are normally sold in 20-foot sections and are cut to fit any desired openings. They are described by their dimensions. For example, to span an opening over a 3-foot-wide window, it may require a lintel that is 3”x 3”x 3’6”x 1/4” (WIDTH x HEIGHT x LENGTH x THICKNESS). Although the window in this scenario is only 3-foot-wide, the lintel must be longer than the opening so as to sit atop of the brick on either side of the window for support, thus requiring a 3’6” lintel in this example. If the lintel were the same length as the opening, it would not be supported by the brick underneath on either side thus not lending support for the brick being laid on the lintel above.

The greater the space of the opening, the larger the lintel may need to be in overall dimensions in order to adequately bear the weight it is holding. For example, a standard size for a lintel that is intended to span a 16-foot garage door is 4” x 6” x 17’ x 3/8”.  Because the back or vertical wall of the lintel is where it gets most of its strength, a flat lintel can bow under its own weight, but an angle iron lintel won’t allow the bottom to bow without crunching the vertical wall of the lintel. Therefore, a 1/4-inch-thick angle iron lintel is actually more supportive than a 1 inch thick, flat lintel.

When installing an angle iron lintel over a garage door or any other opening, there is a process to follow, and if any step in that process is omitted, it will almost certainly lead to a failure of the lintel’s ability to support the weight load.                             


Before installing the lintel, Advantage Masonry consults an on-staff engineer regarding dimensions necessary for each one. Prior to the installation of the lintel, the brick must first be installed on either side of the garage door to an elevation equal to the top of the garage door, and both sides must be perfectly level to each other. Once this is step is completed, it’s then ready for the lintel.

To begin the installation process of the lintel, a small amount of mortar is placed atop of the brick on either side of the garage door. Because the lintel is made from steel, it will expand and contract with the heat and cold; therefore, the ends of the lintel are wrapped with expansion material which allows the lintel to expand and contract without breaking the brick and the mortar.

The lintel is then set in place and leveled into the mortar that was previously placed atop the brick on either end with pre-drilled holes every 16 inches in the back or vertical wall. The header, which is located behind the angle iron lintel and located over a garage door, is constructed of two 2 x 12’s laid on edge and sandwiched together with an equal sized piece of 1/2 inch plywood between them. This is what supports the stud wall framework of the house over the garage door. The angle iron lintel only supports the brick work which sits directly in front of the stud wall.

The next step in the installation process is to connect the lintel with 3/8 inch stainless steel lag bolts and washers to the header every 16 inches. This prevents the lintel from moving out of its intended position, and perhaps, more crucially prevents the lintel from sagging from the weight of the brick during hot conditions. When steel gets hot, its molecules expand, making the lintel vulnerable to sagging under immense weight. At this point, the lintel is in place, it’s level, it’s the correct size to carry the load, and it’s bolted into the header. With the appropriate size of lintel bolted into the header and brick ties throughout the brick work, the lintel DOES NOT SAG.

NOTE: It’s imperative to get the lintel size right. If the lintel is too small, it won’t carry the load, and if it’s too big, its own expansion and contraction will break your brick.


After the lintel is in place and it’s all secured, a moisture barrier covering must be installed to the stud wall above the garage door. The moisture barrier can be made of either 6 mm plastic or Tyvek house wrap. The purpose of the moisture barrier is to trap any condensation that gets into the air space between the back of the brick and the front of the stud wall so that it funnels the condensation to an escape point known as a weep hole. Once the moisture barrier is in place, brick ties, also known as wall ties, are installed. These are metal tabs that are nailed into the vertical 2 x 4 studs and bent into the horizontal mortar joints, also known as bed joints, as the brick is installed. The mortar forms around the brick ties during installation, and this connects the brick wall to the stud wall behind it, preventing the brick from being able to move on any axis.

Advantage Masonry’s final step is to install the brick, strike the mortar joints, wash it, and clean up the mess.

If your home is experiencing a sagging lintel, it can only be due to one or more of these issues, and it must be rectified immediately. If your brick has moved out of its original position in conjunction with a sagging lintel, it can only mean that the brick ties either aren’t there or have failed. Either way, it means the bricks are NOT CONNECTED to the house and are in danger of immanent collapse. This must be corrected immediately in order to prevent loss of property or more importantly, loss of life.

NOTE: If you would like to schedule a free, no obligation inspection with one of our qualified technicians, please click on the link below.

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