On a project with significant square footage and multiple substrate types, bid differences come down to more than the bottom line. Three things to push for in every proposal:
Coating system specification. The bid should name the product, the manufacturer, and the required mil thickness. Technical data sheets, like those available through Sherwin-Williams’ industrial product line, spell out expected lifespan, warranty terms, and surface preparation requirements for each system. A bid without a named specification has no accountability.
Surface prep scope. Power washing, mechanical abrasion, rust treatment, and primer should be listed as distinct items or clearly scoped in writing. When surface prep is a single vague line, what is actually being done is undefined.
Warranty coverage. Standard contractor warranties run one year. Qualifying coating systems support five or ten year warranties when installed per manufacturer specification. Asking about warranty terms tells you how the job is being specified and what the contractor expects out of their own work.
McSweeney’s commercial exterior painting proposals include a defined prep scope, named product specification, and clear warranty terms for every project.