Spray on insulation - Before, choosing an insulation company is very simple. All you have to do is place a bid and choose the company that offers the lowest price. Today, because there are already a number of insulating materials choosing a contractor has become much of a task. It is best that you choose the best company since not all spray on insulation contractors is equal. Spray foam is applied by the mixture of multiple chemicals at a high temperature. An inexperienced or careless spray on insulation contractor could spray on the foam too cold causing it to split and/or lose an air seal.