Had today free to finally get back to my mum and dads with the hope of tiling at some point next week.
Fitted the insulation boards and heat base mat.
Hopefully my sparky mate will be free to help me tomorrow so I can get the cable laid and SLC.
My Dad, being my Dad, doesn't want surface mounted cables like they did when he had the alarm fitted (I'm sure that install is illegal as the wire looks far too thin for the ring main) and he doesn't want the hassle of the other side of the wall chased - fair enough it's wall papered. Think the only way he'll be happy is if we have the spur, thermostat and fan/light switch in a row. So drilled a brick out in the hope that my sparky will be able to feed the cables through the cavity, do his thing and make it all work.