Lintel replacement

Building Type 3: 1920-1940

Inbuilt iron lintels over windows are normally well protected by the facade brickwork, but lintels over basement windows and in some cases over windows in the ground and upper floors can be exposed to the effects of moisture – as a result either of rising ground moisture or of penetrating driving rain connected with e.g. cornice overhangs or holes in the roof.

Long-term exposure to moisture leads to corrosion of the iron beams, which then expand, putting pressure on the brickwork and causing it to crack. At the same time, the load-bearing capacity of the iron beams is weakened. Where the load-bearing capacity has been significantly reduced, the beams must be replaced.

Since the iron beams are an integral part of the facade brickwork, replacement work will normally require an extensive intervention in the building. New iron beams must be rustproof (e.g. galvanised), and an important factor of the repair work will involve the detection of the source of moisture – and thus the cause of damage – and its elimination.

The replacement of iron beams over windows requires the temporary bracing of the facade masonry while the work is in progress. There are various bracing solutions available, each of which must be assessed on the basis of an engineering calculation.

Further information is available from BYG-ERFA, etc.: Masonry structures

Photo: Jesper Engelmark