Backer / Cement board for low level UFH

[StheBrit]

Hi. We have recently bought the ground floor of a Victorian house, about 100 m2. The floors are all laid to very solid floor boards and the ceilings are 3m high. I've had some quotes from a couple of UFH firms, one says they'll lay their product directly onto the exisiting floor boards and the other is adamant we should lay 12mm cement backer board over the entire floor, before laying the UFH. I have no clue who is right, what is the concensus here for this please?

 

[oz-plumber]

Call the forum sponsor - uheat. They may be able to help you.
Or call manufacturers of the heating pipe and see what they say.

I would personally say you need some form of insulation from the floorboards.
You want to make it easier for the heat to rise into the room than go down through the floorboards.

 

[Timmy D]

Whatever floor finish you intend to install will need a solid subfloor. With or without UFH, straight on to floor boards will not end well.

As above, you also want to insulate under the UFH.

Depending on available floor height (which usually isn't much), you’ll likley want to lift floor boards, insulate between joist and cover with 3/4” ply. Then if you’ve got space install the UFH pipe in pre-grooved insulation boards.

 

[gpbeck]

I lusted after underfloor heating for years. If I'd done it just 5 years ago my system would have been incompatible with 2023 current standards and very disruptive to install. I then discovered large 2-2 radiators can be sited unobtrusively and perform brilliantly!