Can I cut my floor heating mat if it’s too large?
NEVER cut the floor heating wire.
The resistance (the measurement of the amount of resistance the electrical current meets as it passes through the wire) for your mat or cable is calculated on the length of the heater. If you cut the wire, it would actually increase the resistance and thereby the temperature. This will cause the wire to overheat and negatively impact the functioning of your floor heating system.
Instead, try pulling the cable off the mesh and spacing the cable every 2 or 2.5 inches apart. Consult your installation manual with further questions.