For hard surfaces, any overhang up to 12" will rely upon the 2/3 rule applies: 2/3 of the material needs to be supported for the 1/3 over hang. A 24" cabinet can safely have up to a 12" overhang without support. For solid surfaces and plastic laminate, any overhang over 6" will need to be support. A solid wood support will be installed under the counter top by The Countertop Factory. Generally any overhang over 12" should be supported. Supports can range from wood corbels to metal 'L' brackets. Customers will be advised if supports are needed at time of measure and these need to be in place before the counter tops are installed. Supports must be installed by the customer, and are not part of the installation services provided by The Countertop Factory.