What to check before quoting a surface-cleaning job

Start with what is underneath. Steel, aluminium, thin sheet metal, laminate, soft or hard wood, brick and natural stone react differently to the same stream. Ask about the age and condition: rot, cracks, loose joints or earlier repairs change what is possible. For buildings and historic objects, check whether the surface is protected and who has to approve the work.

Is it paint, varnish, rust, soot, graffiti, antifouling or general dirt – and how many layers are there? Thickness and adhesion influence time and medium consumption more than the area itself. If nobody knows what the coating is, treat that as an open question, not a detail.

Unknown old coatings may contain hazardous substances. Have them identified and assessed by a competent person before work starts. This guide cannot tell you how to handle them.

Customers describe results in different words: “clean”, “like new”, “bare metal”, “ready to paint”. Agree what it means for this job, ideally with a reference spot or photos. If a new coating follows, ask which preparation its manufacturer requires. Write the agreed result down – it protects both sides.

• Where can the trailer park, and how far does the hose have to reach?
• Is work at height needed, and who provides scaffolding or lifts?
• Indoors or outdoors? Indoors, ventilation and extraction need planning.
• Which working hours are allowed, and is the area accessible during the job?

Look at what is around the surface: neighbours, traffic, plants, water, drains, windows and other equipment. Find out the site rules and local requirements for protection, permits and the collection and disposal of residues. Residues contain the removed coating, so their handling depends on what was on the surface – not only on the medium.

Take photos of the whole surface and close-ups of problem areas before you start, and note the approximate size. Record what the customer told you about the coating and history. Good documentation makes the quote traceable and gives you a basis for comparing the result later.

A trial on a small, agreed spot shows how the surface really reacts and how long the work takes. Agree in advance where it will be done and how the result will be judged. Only then is it realistic to fix a price, a schedule and the expected result for the full job.