What the steels do
Loft conversions almost always need beams to carry the new floor, the existing roof, and sometimes a flat roof dormer above. The engineer sizes them based on spans, loads and bearing.
Padstones and bearings
Steel beams concentrate load. They need padstones — usually engineering brick or pre-cast concrete — at each end to spread that load into the existing wall. Miss this and the wall cracks.
Fire protection
Exposed structural steel in a loft conversion usually needs fire protection — boarded encasement or intumescent paint to the period required. Often missed at first fix.
Frequently asked
They should not. If they have, stop work and get the engineer back on site before anything is built on top.