The timing of electrostatic discharge (ESD) floor resistance testing depends on the flooring system and the purpose of the test. Some manufacturers require checks between installation stages, while final acceptance testing must account for curing and the project’s requirements. ANSI/ESD STM7.1-2020 directs testers to follow the manufacturer’s instructions for proper cure time.
STM7.1-2020 is an ESD Association standard test method (STM) approved by the American National Standards Institute (ANSI). ASTM International publishes the F150 test method.
Why cure time comes first
STM7.1-2020 section 6.2 directs testers to allow proper cure time, if any, following the manufacturer’s instructions before acceptance testing a newly installed flooring system.
Testing before finishes, coatings or adhesives are fully cured may produce resistance measurements that differ from those obtained after full cure. An intermediate installation check and a final acceptance test therefore serve different purposes.
Testing checkpoints in manufacturer instructions
The following examples show how testing fits into different installation sequences. Each instruction applies to the named product, and required tests are distinguished from recommended readings.
Stonkote ESD: readings after the coating becomes tack-free
The Stonkote ESD instructions require the floor to be tested after the coating has been applied. Once the coating is tack-free, point-to-point and point-to-ground readings should be taken.
This is a product-specific checkpoint. It does not establish tack-free condition as the testing criterion for other ESD coatings.
RESUFLOR SCT: an early reading and a later baseline
The RESUFLOR SCT instructions call for surface-resistivity testing after 24 hours to confirm that the system falls within product specifications. The final reading should be taken after a 7-day cure and recorded as a baseline for future audits.
The instructions also state that full coating properties take 14 days to develop. The early check, baseline reading and development of full coating properties are separate milestones.
Stonclad ESD: checks between coats and after the final coat
The Stonclad ESD instructions identify three testing stages:
- After the mortar has cured overnight, surface-resistance testing must be conducted before the first coat of ESD Sealer is applied. All tests must fall below 1 × 10⁵ ohms.
- After the first topcoat has cured overnight, the floor must again be tested for surface resistance before the second coat of ESD Sealer or Stonkote AT5 is applied. All readings should again fall below 1 × 10⁵ ohms.
- After the second coat of ESD Sealer or Stonkote AT5 has cured overnight, the system should be tested one final time.
The first two tests are required installation checks performed before the next coat is applied. The final test is recommended after the second coat cures overnight.
Sikafloor 200 ESD: checking the conductive primer before covering it
When Sikafloor 220W conductive primer is used with Sikafloor 200 ESD, the Sikafloor 200 ESD instructions require conductivity testing of the primed surface before the finish is applied.
The primed surface must achieve less than 10,000 ohms, using the instructions’ stated test-method reference, ANSI/ESD S7.1/ASTM F-150. Sika writes this limit as < 10 × 10³ ohms.
This checks the conductive primer at an intermediate installation stage. It is not a measurement of the completed flooring system.
Testing provisions in FAA and project specifications
FAA flooring: follow the manufacturer’s installation and testing recommendations
Federal Aviation Administration (FAA) standard FAA-STD-019f, dated October 18, 2017, section 5.8.9 requires ESD control floors and floor coverings to be installed, grounded and initially tested by trained installers in accordance with the manufacturer’s recommendations.
This provision ties initial testing to the manufacturer’s instructions rather than assigning one waiting period to every flooring product.
Conductive sparkproof flooring: a specified 30–45-day window
Unified Facilities Guide Specifications (UFGS) section 09 67 23.14, Chemical Resistant Resinous Flooring, includes an electrical-resistance testing provision for conductive sparkproof flooring in section 3.4.1.
Where adopted for a project, it requires testing between 30 and 45 days after installation is completed and before the flooring is used. It references paragraph 12-4.1.3.8(b)(7) of NFPA 99, published by the National Fire Protection Association (NFPA).
The provision addresses facilities requiring conductive sparkproof industrial resinous flooring, with explosive and ammunition facilities given as examples. It does not establish a universal waiting period for ESD floors.
Conductive resinous terrazzo: a specified 30–45-day window
UFGS 09 66 23, Resinous Matrix Terrazzo Flooring, section 3.3 requires testing of conductive resinous terrazzo between 30 and 45 days after installation is completed and before use, where that provision is adopted for the project.
It also references NFPA 99 paragraph 12-4.1.3.8(b)(7).
Both UFGS examples above come from the August 2016 editions with Change 1 dated August 2018. Their timing requirements and cited NFPA paragraph belong to those provisions and should be checked against the specifications governing the project.
Plan the testing checkpoints before installation
Before installation begins, confirm which tests the manufacturer and project specification require, when each test occurs, and what results must be documented. Include any checks that must happen before another layer covers the surface, as well as the testing required for final acceptance.
Craftsman Concrete Floors coordinates testing with the installation sequence and project requirements, including intermediate checks and documented final results where specified.
Frequently Asked Questions
No. STM7.1-2020 directs testers to allow proper cure time, if any, following the manufacturer’s instructions. Testing before finishes, coatings or adhesives are fully cured may produce resistance measurements that differ from those obtained after full cure.
The RESUFLOR SCT instructions call for surface-resistivity testing after 24 hours to confirm that the system falls within product specifications. The final reading should be taken after a 7-day cure and recorded as a baseline for future audits. Full coating properties take 14 days to develop.
Yes. The instructions require surface-resistance testing after the mortar cures overnight and before the first ESD Sealer coat, with all tests below 1 × 10⁵ ohms. Testing is required again after the first topcoat cures overnight and before the second coat, with readings that should again fall below 1 × 10⁵ ohms. A final test is recommended after the second coat cures overnight.
No. The cited UFGS provisions set that window for conductive sparkproof flooring and conductive resinous terrazzo flooring where those provisions are adopted for a project. It is not a universal STM7.1 waiting period.