Q: Some ESD material suppliers claim that Copper Mesh Grid is not required in case of two layer flooring. Is it correct and if so, why only in case of three layer?
A: This question may be off topic. It sounds like you are talking about ESD flooring, not bench or floor matting. If that’s the case, some manufacturers of esd flooring make a conductive backed tile or sheet good. This backing may be so conductive and along with a conductive esd adhesive, they claim that you don’t have to lay down an expensive copper grid. That’s fine. But if I’m installing the floor, I’ll use copper (or aluminum if requested) tape and run a standard grid the length of the room (along the x-axis) and cross it up (y-axis) so as to ground the floor at least once every 2500 square feet or a couple of times per room minimum. I’ve found that this helps prevent hot spots from tile to tile or gives more consistent RTT (Resistance Top-to-Top or Point to Point). One roll of copper tape would enable me to ground a room that was 60’ x 40’ without a problem. If I have more tape to use, I’ll use it. A liberal amount of copper tape and ESD adhesive is provided free of charge with the purchase and installation of an ESD floor from Ground Zero Electrostatics, Inc.
Copper mesh grid just doesn’t apply to 2 layer or 3 layer mats. They use ground cords. One per every 10 feet, I believe.
Q: What is the difference betwen two layer and three layer ESD PVC Mat, and which one will be advisable for flooring?
A: We have a variety of bench and flooring mats and runners. The two and three layer mats would generally refer to our bench or table mats. Our Duro-Stat line is actually a homogenous vinyl ESD matting with great mechanical and electrical properties. But most BM’s are of the two-layer or three-layer type. The top layer would give the mats its resistance to chemicals, resistance to solder, flux, and the ability to keep it clean. The backing would typically promote an anti-skid and durable surface. The three-layer mats are going to have a conductive scrim center layer and work well with most wrist strap constant monitors.
For floor mats and runners, we’ve got our UltraCon Floor Mat which is made of highly conductive rubber. Your flooring mats and runners are going to be typically homogenous and don’t have layers per say. Our Tough One! line is made of embossed homogenous solid vinyl. The exception being our Anti-Fatigue II line, this static dissipative mat is a vinyl mat with a foamed vinyl backing. Our No-Slip II is made of a corrugated slip-resistant vinyl.