De-coupling membrane with UFH

[Rich]

What a head scratcher... Why has the plumber recommended this route? I assume that there is a reason for using these materials? as there are much more suitable materials on the market.

As Jay says, plumbers should stick to plumbing.

 

[Ajax123]

When cement ( in the adhesive) is mixed with water it produces a number of chemicals one of which is sodium hydroxide. Put this in direct contact with alluminium ( the foil on the insulation) and you get an oxidation reaction which evolves hydrogen gas..........your tiles wont stick. Take up the boards and do it properly. Also why on earth has he screwed ply down to the concrete??