Chemical grouting is a broad term used to differentiate cementitious from non-cementitious (“chemical”) grouts.  There are dozens of types of non-cementitious grouts, such as acrylics, silicates, resins, polyurethanes, etc.

Chemical grouting tends to be relatively expensive.  The cost of the grout is generally higher than cement-based grouts, but they are often capable of things that are impossible with cement grout.

When done properly, chemical grouting is a time-proven process that is not harmful to the environment.  Generally speaking, the final in-place materials are inert, and many are approved for use in contact with potable water.  Proper handling of the raw components of chemical grouts is important, and the barrier to entry into chemical grouting is relatively low (often just a paint sprayer and some pails of material), so it’s important to use a contractor who knows what they’re doing.

Because it is a very broad term used to describe anything that’s not a cement-based grout, chemical grouting works in a number of ways, depending on the goal and the material. 

Chemical grouting has two primary uses: controlling water flow through leaks, or binding soils together to increase their strength or decrease their permeability.