Steel beam lintels. The figure shows a lintel with steel beams. The length of the support of the beams on the wall should be 20-25 cm. The space between the beams is filled with brick. Before starting to fill the lintel, brick, mesh the lower flanges of the beams to ensure adhesion of the mortar during subsequent plastering. You do not need a form to make such a lintel (formwork). To prevent the beams from slipping apart, they can be joined with bars or bolts.