How to Specify an ESD Floor That Passes ANSI/ESD S20.20

By Meera Sawhney · August 24, 2026 · 5 min read

An ESD floor specification can look complete while leaving out the details that decide whether the installed system works. A product data sheet may show a resistance value, but ANSI/ESD S20.20 does not qualify a bucket of resin or a finished floor sample in isolation. It evaluates the footwear and flooring system that a person actually uses in the protected area.

That distinction changes what belongs in the specification, what must be tested after installation, and what the facility team must protect during maintenance. This guide explains the two performance measurements, the grounding details that cannot be skipped, and the six items to put in an ESD flooring specification.

Why the product data sheet is not the answer

A resistance figure on a flooring product data sheet typically comes from ANSI/ESD STM7.1, which measures the flooring material by itself. That value can help compare materials, but it is not the same as the result of a person walking across the installed system.

ANSI/ESD S20.20 compliance is decided using the person, their footwear, and the floor together. The conductive or dissipative floor, grounding network, footwear, installation conditions, and cleaning program all affect the result. Specifying only a material number is one of the easiest ways to create a floor that looks compliant on paper but fails system verification in the room.

The two numbers that decide system performance

Two different questions must be answered during verification. Both results matter:

  • System resistance, per ANSI/ESD STM97.1: less than 1.0 x 109 ohms for the person plus footwear plus floor.
  • Peak body voltage, per ANSI/ESD STM97.2: under 100 volts while the person moves across the system.

Resistance describes how readily charge can leave the person through the footwear and floor. Body voltage describes how much charge the complete combination generates while walking. A floor can perform well on one measurement and still miss the other, so a supplier certificate for the material alone cannot replace on-site verification with the facility's actual footwear.

Conductive or dissipative: choose from the hazard assessment

Conductive and dissipative describe resistance bands, not a ranking where lower is always better:

  • Conductive: resistance to ground of 1.0 x 106 ohms or less.
  • Dissipative: above 1.0 x 106 ohms and below 1.0 x 109 ohms.

Faster charge drainage is not automatically the right choice for every operator or every zone. A lower-resistance path across a person near exposed line voltage introduces a shock-hazard question that belongs in the facility's hazard assessment. Many electronics environments select a dissipative band for that reason. Record the reasoning for the selected band in the design documents so the choice can be checked during future audits or process changes.

The grounding detail is not optional

The floor can only perform as designed when the grounding path is continuous. The specification should identify the manufacturer's required copper grounding-strip spacing, how the strips bond to the conductive layer, the conductive primer or adhesive system, and where the connection terminates at building ground.

Ground termination must be completed and documented by someone qualified to make that connection. A break in the strip layout, a missed bond, an incompatible adhesive, or an incomplete termination can leave an area that cannot drain. The problem may not appear at a test point elsewhere in the room, which is why the grounding layout and verification plan should cover the whole protected area.

What can turn off a compliant ESD floor

ESD performance is a maintenance condition, not a permanent visual feature. A clear acrylic floor finish applied later by a maintenance crew can act as an insulating layer over the conductive surface. The floor may still look clean and intact while the electrical path is blocked.

Silicone and oil contamination, unapproved cleaning chemistry, a change in site footwear, damaged grounding connections, and seasonal humidity changes can also move the system result. The handover package should state what products and footwear are approved, what must not be applied, and who is responsible for re-verification after a change.

Facilities with cleanroom or data-center requirements should coordinate the flooring maintenance plan with their existing contamination, access, and equipment-protection procedures. An ESD floor that is maintained outside the facility's broader program will eventually be tested under conditions it was never specified to handle.

Six items for an ESD flooring specification

A useful specification makes the performance requirement testable and assigns responsibility for the details. Include these six items:

  1. Reference the governing standard and test method. Reference ANSI/ESD S20.20 and require system verification per STM97.1 and STM97.2 using the facility's actual footwear, not only a supplier's material sample or certificate.
  2. State the resistance band and the reason for it. Identify conductive or dissipative performance for each zone, and record the shock-hazard reasoning from the facility's hazard assessment.
  3. Detail the grounding network. Show strip layout, spacing, bonding method, conductive layer requirements, termination location, and the party responsible for making and documenting the building-ground connection.
  4. Require post-installation verification on site. Define the test locations, equipment, environmental conditions, footwear, acceptance criteria, and report that must be delivered before the area is released.
  5. Protect the finish during handover. Put the no-acrylic-finish restriction and approved cleaning chemistry in the handover documents, maintenance instructions, and signage for the protected space.
  6. Set a re-verification interval. State how often the floor and footwear system will be checked, and require a new review after a change to footwear, cleaning products, floor finish, grounding, process, or room use.

What to verify before the room is released

Post-installation testing should be planned before the flooring work begins. The verification record should identify the zones tested, the footwear used, the test method, the test conditions, and the measured results. It should also document any locations that were repaired or retested.

Walk the room with the facility team after testing. Confirm that grounding points are accessible, transitions are protected, the maintenance restrictions are understood, and the approved footwear is available. This handover is where the installed ESD flooring system becomes part of the facility's operating program instead of remaining a contractor deliverable.

Specify the system, then protect the result

An ESD floor is not qualified by a resin label or a single resistance number. The system must be designed around the zone hazard, grounded continuously, verified with the facility's actual footwear, and maintained without insulating finishes or unapproved cleaning products.

DTI installs and verifies static-control flooring for manufacturing, electronics, laboratory, and process environments nationwide. Book a floor-condition assessment to review an existing ESD floor or discuss the performance requirements for a new specification.