Question: If mafia blocks are used for a retaining wall, can they be drilled into for fence posts or are they too brittle for drilling?
Answer: True mafia blocks are concrete blocks without any reinforcement. Their mass is used to provide stability to walls and barricades. Mafia blocks can be drilled with common concrete core drilling equipment. Concrete is an easy material to drill into if the proper type core bit is used. A core bit is a circular tube with cutting teeth on one end and a receiver shaft designed to fit into heavy duty drills on the other. The use of a concrete coring machine, which can be rented from any construction equipment rental company, will make the task easier. Water is normally sprayed, as the cutting of the concrete takes place, to cool the concrete cutting bit or core bit.
There are also specialty contractors that perform concrete coring as well as cutting operations. Just to provide you with some additional confidence regarding this operation, a normal commercial installation of fencing on the top of a concrete wall, is in many cases cored to accommodate the fencing posts. These posts are then epoxied into the cored concrete for a very professional and stable installation. The installation of sleeves into the top of the concrete wall is sometimes used, however, this requires precise coordination of the fence posts and the sleeve placement. In most cases, there is a need for several cored concrete holes to be drilled, even if sleeves are used due to the lack of proper coordination.