Standard dimensions of flat lintel beams of H+H P4,4–0,60 for load-bearing walls, according to admission. Calculation value of dead load according to DIN 1055: 7,2 kN/m³, λ  = 0,16 W/(mK).

For other thickness of load-bearing walls, several flat lintel beams can be set side by side if the extension is built on the entire thickness of the lintel.