Silos, smokestacks, grain bins and tanks get treated as just another exterior surface until somebody prices the access. They are a separate discipline, and the things that make them difficult have very little to do with the coating itself.
Access decides the project
On a building you work from the ground or from a lift. On a 100 foot silo neither is straightforward. Access might mean rigging, suspended platforms, or lifts with the reach and the ground conditions to support them. That decision drives the schedule, the crew size and a large share of the cost, and it is settled during the walk-round rather than on paper.
It also constrains the working day. A crew on a suspended platform works to different weather limits than one on the ground.
Surface preparation happens up there too
The coating will only last as long as the preparation underneath it, and all of that has to be done at height. Rust and failed coating come off with needle guns and rotary scalers. Cleaning is done by pressure washing or dry ice blasting depending on the substrate and what is inside the structure.
Containment matters more than on a building, because everything removed falls a long way and spreads. On a food site, that includes containing the debris away from product areas entirely.
Coating selection
These structures face a combination most surfaces do not: full UV exposure on all sides, wind-driven rain, thermal cycling as the sun moves around them, and in the case of smokestacks, heat and flue products from inside.
Grain bins and food-related tanks add another consideration, which is what the structure holds. A coating on the exterior of a food storage structure still has to be chosen with the contents and the audit regime in mind.
The weather window
Every exterior coating has temperature and humidity limits for application and cure. On a tall structure those limits are stricter, because wind affects both the spray and the crew, and the surface temperature on the sunny side can differ substantially from the shaded side at the same moment.
In Wisconsin, Illinois and Minnesota that narrows the season considerably, which is why this work gets booked well ahead.
What a quote should itemise
Because so much of the cost is not painting, ask for the access method and its cost, the preparation standard, the containment approach, the coating system by layer, and what happens to the schedule if weather stops work. A quote that gives a square foot rate and nothing else has not been thought through.
We handle silo, smokestack, grain bin and tank painting alongside industrial facility and commercial building work, and silo blasting and coating for food sites.
Read about commercial exterior painting and food plant services, or ask us to look at your structure.
