1. How long have you been cleaning decks? 
Over 80% of deck cleaning and pressure washing companies fail within their first five years of business due to bad planning, lawsuits or bad service.

 2. Do you have proper training for cleaning decks?
cleaning isn't as simple as most people think. Too much pressure can force water behind siding or damage wood and even concrete!

 3. Do you use professional grade cleaners that are designed for the surface you are cleaning?
Many contractors use home made recipes, bleach or other products from big box stores for cleaning decks.  The products can cause damage to the deck surface.   Professional grade cleaning products are designed to give better results and outperform products from local hardware stores.  If your paying for quality service,  you deserve to get the best products available!

 4. What type of deck sealers do you use on wood surfaces? 
Manufacturers spend millions of dollars a year to promote their products but they don't tell you that linseed oil, (one of the most popular oils in deck sealers) is actually food for mildew!  They also don't say that surface coating agents which are usually found in hardware stores may actually allow problems to occure to the woods natural fibers.

 5. Are you licensed, bonded and insured?
Maryland law requires anyone that seals decks or does any type of repairs to hold a Maryland Home Improvement License.  Unfortunately the MHIC does not require it for the cleaning process which is where most damage occurs.  Insurance is your only protection so make sure they have it!