Door and window openings in the walls are covered with vaulted or flat lintels.
If the windows have sashes that open into the room, the pillars and the lintel are made with jambs. The window sill wall is finished from the outside of the window with an external window sill, and from the inside - an internal window sill (window sill),
The choice of a lintel depends on the type of building structure (walls and ceilings), its destiny, the width of the opening and the architectural shape of the building and walls.
Vaulted lintels are made in the form of arches: staple, semicircular, elliptical, baskets, pointed arches, etc.. In the vaulted lintels (arches) compressive forces occur, therefore, the bricks and stones are placed with pressure planes perpendicular to this force. In the past, vaulted lintels were made of stones cut in the form of wedges. Nowadays, stone arches are very rarely made, and the wedges are replaced with bricks. The wedge is obtained by thickening the upper part of the joints between the bricks. Vaulted lintels with larger spans usually have a variable thickness decreasing from the head to the key.
The vaulted lintels are made on the formwork. The upper surface of the formwork is shaped like a lintel and rests on the scaffolding. The construction of the vaulted lintel begins with both of its headboards and ends with embedding the keystones in the lintel key. The correct position of the supporting joints in the arch is determined with a string or a movable one, a patch tied to the nail driven into the board, e.g.. in the center of the circle.