The most common potassium silicate has the formula K2SiO3, samples of which contain varying amounts of water.

Impregnation of wood with a potassium silicate solution is an easy and low-cost way for rendering the woodwork of houses secure against catching fire.

It is also used as a supplement (in conjunction with normal fertilizer) for the numerous benefits that increasing the availability of silicon compounds has.

[3] The thicker cell walls of the plant also provides an added mechanical resistance to sap-sucking insects (e.g. spider mite) and various pathogenic fungi (e.g. powdery mildew).

Some metal cleaning formulations use potassium silicate, which also serves as a corrosion inhibitor.