Tom M. asks:
What is the proper treatment of control joints when installing an ESD concrete coating system? Joint filler is not dissipative and it is often not practical to ground within every joint-bordered area.
Thanks for your question. It is important to remember that ESD systems are installed over a coat or two of insulative epoxy. The floor is then ground to earth groundpoints. So ideally, it is best to install the joint material before applying the topcoat of Florothane CR 250 ESD. This thin film specialty floor coating will bridge the joint material, providing a dissipative surface throughout the concrete floor. Florothane CR 250 ESD has enough flexibility to allow normal joint movement.
In circumstances where the joint material must be installed after the ESD system is already placed, each isolated slab should either be given its own earth ground (as you say, not very practical), or should be “reconnected” to adjacent slabs. The latter can be achieved by bridging the joints using ESD strapping.
I hope this answers your question. Please feel free to call me at 1-800-FLOROCK (356-7625) with any further questions! If you need commercial floor coatings, call us.
Technical Service Representative