A: (This question comes with a lot scrutiny & debate, and is by far on of the most difficult to answer.) Here is my professional opinion based on decades of experience: There is more to pressure washing than just spraying water on your home or deck and it requires specialized equipment and in some cases the use of biodegradable cleaning products which are safe for children, pets and plants. In the hands of a professional contractor with knowledge, experience and a trained eye, a pressure washer is a vital tool for cleaning & preparing your home, deck, and other surfaces prior to applying a primer or finish product. Pressure washing allows you to clean the surface quickly & effectively by utilizing low & high pressure techniques to avoid damage to the substrate. Without being too specific there are several precautions that must be taken prior to and during the preparation of the surface. Over time many houses accumulate a thin layer of grime (and even mold) from dirt, debris, insects, oxidation & other various sources. While this residue in most cases won’t inflict any damage, it is important to remove it before painting your home, refinishing or restoring your deck, etc. A clean, properly prepared surface will increase the adhesion, appearance, and longevity of the product that you apply for years to come.