Genesis 11:3 - Ellicott's Commentary On The Whole Bible

Let us make brick, and burn them throughly. — Heb., for a burning. Bricks in the East usually are simply dried in the sun, and this produces a sufficiently durable building material. It marks a great progress in the arts of civilisation that these nomads had learned that clay when burnt becomes insoluble; and their buildings with “slime,” or native pitch, for cement would be virtually indestructible. In fact, Mr. Layard says that at Birs-Nimroud it was scarcely possible to detach the bricks one from another, as the cement by which they were united was most tenacious (Nineveh and Babylon, p. 499).