Questions to Ask When Choosing a Pressure Washing Service

Q: 1. Do you carry public liability insurance?

This is non-negotiable. Public liability insurance protects you if the contractor causes damage to your property or injures someone while working on site. Ask specifically for the policy details — how much cover it provides (£1 million minimum is standard; £2 million or more is better for larger jobs) and whether it covers the type of work you're having done. Ask to see a copy or a certificate of insurance before they start. Any reputable company will hand this over without hesitation.

Q: 2. What equipment and pressure settings do you use?

Not all surfaces need the same pressure. High-pressure washing on older Scottish sandstone or soft mortar can strip out pointing and cause serious structural damage. A knowledgeable operator should be able to tell you the PSI (pounds per square inch) they use for different surfaces and explain why. Soft washing — using lower pressure combined with specialist cleaning solutions — is often the better choice for roofs, render, and older stonework. If they give you a blank look when you ask about this, look elsewhere.

Q: 4. Do you use any cleaning chemicals, and are they safe for my garden and drainage?

Many effective pressure washing treatments involve biocidal or detergent-based solutions to kill moss and algae at the root. These can harm plants, lawns, and aquatic life if they enter surface drains. In Scotland, SEPA (the Scottish Environment Protection Agency) sets rules on what can legally enter the drainage system. Ask the contractor what products they use, whether they are COSHH-compliant, and what steps they take to protect nearby planting and drainage channels. A good operator will have thought about this already.

Hiring a pressure washing company without asking the right questions first is how you end up with damaged pointing, a flooded driveway, or no recourse when something goes wrong. A few minutes of questions before you book can save you significant money and hassle — especially given Scotland's weather, where moss, algae, and grime build up faster than almost anywhere else in the UK.

1. Do you carry public liability insurance?

This is non-negotiable. Public liability insurance protects you if the contractor causes damage to your property or injures someone while working on site. Ask specifically for the policy details — how much cover it provides (£1 million minimum is standard; £2 million or more is better for larger jobs) and whether it covers the type of work you're having done. Ask to see a copy or a certificate of insurance before they start. Any reputable company will hand this over without hesitation.

Most important question you can ask: "Can you send me proof of your current public liability insurance before we confirm the booking?" A company that stalls or makes excuses is one to avoid.

2. What equipment and pressure settings do you use?

Not all surfaces need the same pressure. High-pressure washing on older Scottish sandstone or soft mortar can strip out pointing and cause serious structural damage. A knowledgeable operator should be able to tell you the PSI (pounds per square inch) they use for different surfaces and explain why. Soft washing — using lower pressure combined with specialist cleaning solutions — is often the better choice for roofs, render, and older stonework. If they give you a blank look when you ask about this, look elsewhere.

3. Have you worked on this type of surface before?

Edinburgh and the central belt have a high proportion of sandstone tenements, slate roofs, block-paved driveways, and concrete render. Each behaves differently under pressure. Ask for specific examples of similar jobs they have completed — a driveway clean is very different from treating a moss-covered slate roof or removing algae from a shared close. If they can point to recent local work, even better.

4. Do you use any cleaning chemicals, and are they safe for my garden and drainage?

Many effective pressure washing treatments involve biocidal or detergent-based solutions to kill moss and algae at the root. These can harm plants, lawns, and aquatic life if they enter surface drains. In Scotland, SEPA (the Scottish Environment Protection Agency) sets rules on what can legally enter the drainage system. Ask the contractor what products they use, whether they are COSHH-compliant, and what steps they take to protect nearby planting and drainage channels. A good operator will have thought about this already.

5. Will you carry out a site assessment before quoting?

A reliable contractor should want to see the job before giving a final price. This matters because access, surface condition, the extent of moss or staining, and the proximity of windows and doors all affect the time, equipment, and methods needed. Beware of very low quotes given without a site visit — they often come with hidden charges or indicate the contractor hasn't properly understood the scope of work.

6. What does the price include, and what doesn't it?

Get a written quote that spells out exactly what is and isn't covered. Ask whether post-treatment products (such as algae inhibitors or sealants) are included, who clears away the loosened debris, and whether VAT is included in the quoted price. In Scotland, it's also worth confirming whether any access equipment — scaffolding, cherry pickers — forms part of the cost if your property has height or access challenges.

7. How long have you been trading, and can you provide references?

Longevity isn't everything, but a company that has been operating for several years in your area is more likely to have a track record you can check. Ask for two or three references from recent customers, ideally local ones, and actually follow up with them. Online reviews on Google or Checkatrade are helpful, but a direct conversation with a previous customer tells you far more about punctuality, tidiness, and aftercare.

8. Are you a member of any trade body or accredited scheme?

There is no single mandatory licence for pressure washing in the UK, but membership of bodies such as the Federation of Window Cleaners or accreditation through schemes like TrustMark indicates a contractor who has agreed to a code of practice. Some contractors also hold relevant SVQ (Scottish Vocational Qualification) qualifications in cleaning or property maintenance. It's not a dealbreaker if they aren't members of anything, but it's a positive sign if they are.

Checklist at a glance

Do you carry public liability insurance, and can I see proof?
What pressure settings and equipment do you use for different surfaces?
Have you worked on this type of surface or property before?
What cleaning chemicals do you use, and are they COSHH-compliant and drainage-safe?
Will you visit the site before giving a final quote?
What does the price include — VAT, debris removal, post-treatment products?
How long have you been trading, and can you provide references?
Are you a member of any trade body or accreditation scheme?

Ready to find someone local you can rely on? Find a trusted pressure washing service in Edinburgh through Found Local, where you can compare local companies and read genuine customer reviews before you book.