Tank, silo and vessel cleaning
What tank and silo cleaning involves, why it is priced per entry rather than per square foot, and the safety arrangements that make up most of the cost.
Tank, silo and vessel cleaning is the most specialised corner of the industrial cleaning market and the one where price comparison is least useful. Two quotes for the same vessel can differ by a factor of three because they assume different entry methods.
Unlike interior building cleaning, this work is almost never priced per square foot. It is priced per entry, per vessel or per shift, because the cost is driven by the procedure rather than by the surface area.
Where the cost actually sits
On a typical confined-space vessel clean, the cleaning itself is a minority of the invoice. The majority is the apparatus around it.
- Isolation and lockout of the vessel, including verification that it is genuinely isolated.
- Atmospheric testing before entry and continuous monitoring during it.
- The entry permit, the authorised entrant, and the attendant who never enters and never leaves.
- Standby rescue provision, which for many vessels means a dedicated rescue team on site for the duration.
- Ventilation equipment, breathing apparatus and non-sparking tools where the residue is flammable.
- Containment, classification and lawful disposal of whatever comes out.
Methods, and why they change the price
No-entry cleaning, using rotating nozzles or automated tank-cleaning heads lowered through an existing opening, avoids the entry procedure entirely and is dramatically cheaper where it is feasible. It is not feasible for every residue or every vessel geometry.
Manual entry cleaning is the fallback and carries the full permit-required confined space apparatus described above. When you ask for quotes, ask each contractor which method they have assumed. A no-entry quote and a manual-entry quote are not comparable numbers, and a contractor who has assumed no-entry on a vessel that turns out to need entry will re-quote once they are on site.
Source: OSHA, Confined Spaces overview, checked 2026-07-29
Before you request quotes
- Know the vessel's last contents, and have the safety data sheet ready.
- Know the access points, their diameters, and whether any are at height.
- Know whether the vessel can be taken out of service and for how long.
- Know whether you have a site confined-space permit system or expect the contractor to bring one.
- Decide who is disposing of the residue, because that liability is worth more than the cleaning fee.