Choosing a commercial cleaner on price alone is how buildings end up changing supplier every year. The things that actually determine whether a contract works are all checkable before you sign.
None of these questions are awkward to ask. A supplier who is set up properly will answer all five in writing without hesitation, and that response time is itself useful information.
The short version
- Ask for insurance certificates before the first visit, not after an incident
- Confirm vetting arrangements where your site requires them
- Get the sickness and holiday cover arrangement in writing
- Check what equipment they own rather than hire
- Ask which method they use on each surface and why
- Check they will put a scope and fixed price in writing
Insurance, in writing and current
Public liability and employers' liability cover should be evidenced by certificate before anyone sets foot on site. Check the dates, not just that a document exists.
For floor work specifically, insurance matters more than people assume, because the equipment involves water, power and heavy machinery moving through a building at night with nobody else around.
Vetting and who actually attends
Ask who will be on site, whether they are employed or subcontracted, and what vetting has been done. Schools, care settings and sites with confidential material often need DBS checked operatives, and that needs establishing before the first visit rather than at the door.
Also ask whether the same team attends each time. Continuity is a genuine quality factor, because a team that knows a building works faster and misses less.
Cover when someone is off
This is the question most buyers forget and the one that causes the most friction later. A one person operation with no cover arrangement will simply miss visits during illness or holiday.
Get the answer in writing. A replacement operative, or a rescheduled visit inside a stated window, are both acceptable. No answer is not.
Equipment and method
Ask what equipment they own. Contractors who own their machines can schedule freely and maintain their kit. Contractors who hire per job are constrained by availability and often by cost.
Then ask which method they would use on each surface in your building and why. The answer tells you quickly whether you are talking to someone who understands the difference between rubber, safety vinyl, stone, carpet tile and sheet carpet, or someone who intends to mop all of it.
- Certificates of insurance, current and named
- Vetting arrangements appropriate to your site
- Written cover arrangement for sickness and holidays
- Owned commercial equipment rather than per job hire
- A method explained per surface, with expected drying times
- RAMS supplied and site specific
- A written scope and a fixed price per visit
References and realistic promises
Ask for references from sites of a similar type, and ask those sites the one question that matters: do they turn up when they said they would.
Be wary of promises that are too clean. Any contractor who guarantees every stain will come out has either not seen your floor or is going to disappoint you. Permanent dye damage, bleaching and delamination are not cleaning problems and no method fixes them.