How to install a floor heating mat around a drain in a shower ?
As a general rule, when it comes to floor heating installations in showers you must always make sure the mat stays away from the drain.
First, do not cut the wire. Simply separate the wire from the mesh and remove the unusable mesh from the mat. Secondly, now that you have freed the wire, you can install the wire around the area using hot-glue or tape to secure the cable away from the drain or screw-mounts.
Lastly, never cross flat or linear drains and make sure to completely cover the heating wire with thinset. Refer to the installation manual for more information.