I've never installed the mat itself. The tile guys install them and I wire them.
No person, firm or corporation shall enter into, engage in, or work at the business or occupation of installing wires, conduits, apparatus, devices, fixtures, or other appliances for carrying or using electricity for light, heat, power, fire warning or security system purposes, unless such person, firm or corporation shall be licensed by the state examiners of electricians
So the tile guys are licenesed electrians?