The requirement almost always arrives in a document

Nobody wakes up wanting an ESD floor. It shows up as an audit finding, a customer contract clause, a new line that has never had a qualified floor, or a code that applies to the room. Which document you are answering to changes the band, the evidence and the price.

2.5 x 10⁴ to 1.0 x 10⁶ohmsANSI/ESD STM7.1 / ASTM D257 (as cited on manufacturer TDS)

under 1.0 x 10⁹ohmsANSI/ESD STM97.1

under 100voltsANSI/ESD STM97.2

Electronics manufacturing

Board assembly, rework benches and test floors handling ESD sensitive parts.

Semiconductor and fab

Wafer handling, probe and assembly areas inside a controlled environment.

Aerospace and avionics

Avionics build and MRO areas where an ESD program is contract language.

Munitions and energetics

Load, assemble and pack areas where a spark itself is the hazard.

Data centers and network rooms

Equipment positions, network operations floors and 911 dispatch centers.

Cleanrooms and medical device

Classified space that also has to hold a resistance specification.

Aviation and FAA facilities

Towers and communications rooms with a higher floor resistance floor.

Pharmaceutical and laboratory

Instrument rooms and production suites with static sensitive processes.

S20.20 qualifies a system, not a surface. The person and their footwear are inside the measurement.