laje

Laje is a term used in Portuguese-speaking regions to denote a flat, horizontal panel of stone or concrete used in construction. A laje can be a natural rock slab quarried and finished for use as a floor, roof, or paving, or it can be a manufactured concrete slab cast in place or in a factory. The word is common in Brazil and Portugal and is employed across various Lusophone countries.

Typical applications include floors and ceilings in buildings, roof decks, stair landings, balconies, and outdoor paving. Concrete slabs are designed and constructed as structural elements, sometimes reinforced with steel (laje de concreto armado) and sometimes left as solid slabs (laje maciça). A ribbed variant (laje nervurada) uses a system of ribs to reduce weight while maintaining strength.

Materials can be natural stone slabs, such as granite or slate, or concrete, sometimes finished with plaster or waterproofing coatings, depending on location and use. The choice of slab type depends on factors like load, span, climate, and cost.

Although most often a construction term, laje also appears in regional place names in Portuguese-speaking areas and as a generic term for flat stone in paving and landscape contexts.