How Long the pressure washing service has been in Business : This is important for a couple of reasons. I do believe you have to start somewhere, but often times over the years, we have seen 'Fly by Night' companies come and go. And to be honest, the last thing you want is to have someone brand new to the trade working on your largest investment with zero training. It's okay to ask how long they have been doing this, or who did they work for previously. Without some sort of training, it is VERY easy to cause damage to your home or to themselves.
Are they Insured: Now this should go without saying, having the proper insurance is so important. If damage is caused to your property, you definitely want to ensure it is covered and the damaged areas can be replaced without the homeowner having to float the bill. But not only ask for proof of insurance, call the insurance company to verify, too many times I've seen 'companies' pay for just the first month only to get the certificate.
Do they have a License: The pressure washing industry, much like lawn care, is very easy to get into. Believe me when I say there are a bunch of so called companies out there that aren't even companies. A quick call or email to your county office and now days even online and you will have your answer.
Do they have Workmans Comp: Another important factor, the last thing anyone wants is to see someone injured or hurt. Verifying that the employees are covered can save you thousands in medical bills if the injured party decides to sue. This like a license, is a quick call or internet search on the States website will reveal the answer.
Equipment needed to pressure wash a house: We've all heard the phrase, " the right equipment for the right job" this applies here as well, too much pressure, or too little will either damage your home or not get it clean. Generally speaking, when washing a house, p.s.i. doesn't matter, the gallons per minute is where its at. The GPM equates to speed, where the p.s.i. equates to power.. You don't want a lot of p.s.i. on vinyl siding or wood. Pressure is great for concrete, but not on your house, fence or deck.
Chemicals needed to wash your house: Never let a company tell you," its proprietary" or "special blend" even, "oh, its our own house mix, its a secret". As a homeowner, YOU have every right to know what is being used on your home. Simple as that. The primary ingredient we all use is sodium-hypochlorite (bleach). The bleach you use in your laundry is around 3%SH, where what we use averages around 10%-12%, mixed with water and a surfactant to help it cling a little better.
How to pressure wash your house: This is another important bit of knowledge. The recommended method is what's called a down stream or softwash. This uses low-pressure to apply the soap and low- pressure to rinse. If done properly this wont damage your home. There is no need to get on ladders, depending on your machine, you can wash safely from ground, even a two or three story home. NEVER apply too much pressure to a home.
How much does it cost to pressure wash your home: Now this can be a big variable. A LOT of things go into pricing such as square footage, material of your home (i.e.- A vinyl siding home will be cheaper than a stucco home). On average ,here in Knoxville, for a 2,800sqft vinyl siding home, you can expect to pay $250 - $350, where as a stucco home of the same size $350 - $500. For pressure washing a driveway anywhere from $75 - $600 depending on the size. Most companies do have a sqft price of .10 - .17 cents. Like concrete a deck can run anywhere from $150 and up depending on size and type (some intricate spindles add cost) as well as levels, etc..
Final Note: It's always best to get more than one estimate, but most importantly go with your gut feeling. If your 'Spidey senses' are tingling, don't ignore it because of price. Ask for references, do some research of previous work. Don't always go by reviews, you'd be surprised how easy 'good reviews' can be purchased.