Starting a pressure washing business in the U.K. - a few questions

[cj]

• What kind of insurance do I need in order to carry out work on residential/commercial properties (U.K.)
• What machine would you recommend I purchase. Initially I’m not looking for anything too fancy/overpowered, something that will do a good job but won’t break the bank. I’m looking around the £2/£3k price range.
• What is the best way to get clients? I’m thinking of posting leaflets in wealthy neighbourhoods to start with, then once I’ve built some capital, I’d like to invest in advertising (Facebook, google ads, posters in public spaces etc).
• How lucrative can is this business in the U.K.? Is there even much competition in the U.K.? I will be covering London and the surrounding area. I understand I will have to do most of the work myself to begin with (I work a full time job so I will have to do most of the work on weekends). Long term, I’d like to hire more people and scale the business up - is this a realistic goal?
• Is it better to charge clients per sq foot or time spent? What’s a good price to set in order to stay competitive?
• What kind of PPE will I need? Gloves, protective eyewear, sturdy shoes etc.
• What’s the best way to accept payment? Cash, bank transfer etc? Should you typically take payment before or after the job? Should I also take deposits when they book?
• Can this business still run during the wet/cold months? (The U.K. has a lot of these months).
• Do you think a website is a must? Could I operate with just an email, phone number and social media presence?
• Is there anything else you think I need to cover before I jump into this business?