Rock removal and rock braking are now easy thanks to Expando a new idea. Expando allows users a new labour saving way to brake up trouble some rock and concrete. Simply Drill Mix and pour. Expando grout when in a confined space increases in pressure untill the rock or concrete brake. Cracking time varys from 6 to 8 hours as the mortar sets up. Generaly fill and the next day see the results. This product can be used where machines cant access or places where noise and vibration are a problem. You wont need any permits and training is as easy as watching the vidio. So when rocks or concrete are a problem for you look into Expando. The web site give more detail and mds . www.expando.com.au