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Learn more about using expanding grout for your next rock breaking project!


About our Expanding Grout

Expanding grout (also known as expansive mortar or rock-breaking grout), is a non-explosive demolition agent used in the rock breaking industry. It is designed to fracture and break up rocks and concrete without the need for traditional blasting methods.

Expanding grout typically consists of a powdered mixture composed of cementitious materials, such as calcium oxide or calcium hydroxide, along with a small amount of water. When mixed together and poured into pre-drilled holes in the rock or concrete, the grout undergoes a controlled expansion process.

The expansion is a result of a chemical reaction that occurs when water is added to the grout mixture. This reaction generates a large amount of heat and causes the mixture to expand, exerting significant pressure on the surrounding rock or concrete. Over time, this pressure leads to the cracking and breaking of the material.

One of the primary advantages of expanding grout over traditional blasting methods is its non-explosive nature. This makes it safer to use in areas where blasting may not be permitted, such as in urban or environmentally sensitive locations. It eliminates the risks associated with flying debris, shockwaves, and the release of harmful gases that are typically associated with explosives.

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Here’s What Our Partners are Saying

After researching other grouts, we were so happy to find Rock Buster’s ROCK XX. The owner and the crew were friendly and helped us understand everything about the product, and how it saved us a ton of money on efficiencies on our large rock demo projects.


We used ROCK X to help demo the thick slab foundation of our old house! Fair prices – best I’ve seen for expanding grout. We will definitely recommend Rock Busters to all our fellow contractors!


rockbusters does excellent work! the bedrock we needed demoed is perfectly gone!