The use of explosives has long been accepted as a means for demolition of reinforced concrete foundations, bridges, bridge piers, concrete and brick stacks, and locks and dams. Their use as a safe and quick way to demolish concrete and masonry structures gained in popularity after World War II and has gained rapidly since the late sixties. One of the more recently accepted methods for demolition of concrete, masonry and steel frame buildings is by implosion with the use f explosives. With the development of newer and safer products as well as better techniques for using them, it has become easier to sell the customer, owner, and governmental agencies on their use. Anyone contemplating use of the services of an explosive demolition contractor should investigate his work by asking for references and contacting previous customers. Amounts of insurance coverage and the name of the carrier should be determined. The customer may also want to ask for a performance bond in the amount of the contract; if he does, he must be prepared for the cost of the bonding to be added to the price of the contract. In the event the customer is doing the hole drilling or preparation of a building for implosion, the demolition contractor should provide a qualified supervisor on site for at least a week prior to the blast, or drop, to make sure all preparations meet his requirements. This will prevent working overtime to meet a blast schedule and will bring about better relations between the two contractors. A contractor who finds it necessary to remove an old building to make way for new construction should inspect the building and surrounding area for the following: type of construction, size of the building, presence or absence of a basement, proximity of other structures, and utilities. After the inspection has been made and the above basic facts considered, local governmental agencies should be contacted for their approval of the use of explosives. The next step is to contact several explosive demolition contractors and have them inspect the building. A reputable demolition contractor will generally make a charge for the inspection trip but this will be credited back to the bid price if he is the successful bidder. Explosive demolition is done in basically the same way by all explosive contractors but each has his own variations.