incombustible

The cruel lesson: Invest in incombustible masonry and stone, or pay the fiery piper.

And yes, stone is an incombustible material; but with high heat it might start cracking here and there.

“As soon as the building is higher than the firefighters’ ladders, it has to be conceived with an incombustible material,” a caption says.

The water which a plant contains and the incombustible portions, the mineral matters or ash, are taken directly from the soil by means of the roots.

Another very important application of soluble silicates is the rendering of wood incombustible.