Casting instead of bricking: when a monolithic lining beats brickwork

Brickwork or monolithic castable? When lining an aluminium furnace, this question often decides years of service life. In a recent project we lined a melting area whose old fireclay brickwork had failed exactly where it was predictable: in the joints. A metre of bricked wall quickly has 20 to 30 joints — each one a possible route for infiltrated aluminium and growing corundum.

Three points that decide the construction method

• The joint is the weak point, not the brick. A monolithically cast lining is jointless — no continuous infiltration route across several metres.
• Casting is not a given: it calls for anchoring matched to the loads, exact formwork and a controlled first heat-up over two to five days.
• The construction method is chosen zone by zone: jointless castable in the zones with direct melt contact, shaped bricks where dimensional accuracy or a later partial replacement is the priority.