In buildings with masonry cladding ( brick wall), there are two types of steel angles (angle iron) namely the steel lintels located above the openings and the structural steel angles which are normally fixed against the concrete slabs of the floors .
The lintels above the openings (doors and windows) are not fixed against the structure, they rest freely on the masonry wall on either side. These steel lintels support the masonry above the openings. However, structural steel angles are metallic elements fixed against the concrete slabs of each storey to support the masonry in buildings that are over 11 m in height (buildings three storeys and above).
So in buildings with three or more storeys, you need to fix a steel angle iron to each storey (about 3 m). Under each of these angles, you have to leave a space of about 1 centimeter without mortar. These spaces (under each angle iron) must be filled with sealing joints to prevent water from infiltrating the wall. A waterproofing system made up of a waterproofing flashing and weepers on the first row of bricks must be installed on each angle. These installations must be carried out according to the rules of the art.
Steel lintels and angles are essential elements in the masonry work. Corrosion of these elements is the most important problem. When the corrosion of the steel lintels begins, these elements will lose a layer of steel on the surface. Corrosion causes deformation of the lintels and angles and consequently the appearance of cracks in the masonry adjacent to the lintels and angles. In addition, the mortar joints start to come out of place due to the deformation in the angles. For this reason, the mortar joints come loose from the masonry where there are corroded lintels and angles.
Corrosion of steel lintels and angles affects the capacity and structural integrity of these elements. This weakness causes the masonry to collapse over time and the presence of long shears in the masonry.
Intervention is needed before the problem gets worse. Therefore, it is necessary to carry out maintenance work or necessary replacements for these elements.