milled in underfloor heating- any experience?

[Malbab]

posting in property and home: we are looking at wet UHF with tiled floor, came across milled ( cutting grooves in screed) over existing concrete floor ( which we have under the tiles) and putting the pipes in and pouring levelling compound over it and re tiling, this is instead of overlay boards that seem far more widely used; advantage is the floor height is not raised, and no need to trim doors to adjust the height etc; our house is built in 2002 and there must be some floor insulation as per building regs then, but obvs not as insulated as newer homes so wondering about the energy efficiency. anyone used the milled in option to set UFH and how has the experience bee, energy bills etc? appreciate any help, thanks :)

I thought this was the way forward for us but everyone I spoke to (builder, Engineer, architect etc) said no due to insulation needed. To the extent I actually thought that it wasn’t possible to do or against building regs (seemed sensible to me as concrete holds thermal mass but I’m clearly showing my ignorance). We ended up with boards into which the pipes were inlaid and then engineered wood flooring went straight down on top. The total height added was under 18mm.

Hi cantsleep
Thank U, yes that is my worry too about the energy efficiency, please may I ask how old is your house cos it seems pointless to do mulled in UFH in any house built pre 1990s but newer homes may be possible ?!
Also with your overlay which boards did U use please we are advised minimum 18 mm boards and with screed , uncoupling membrane adhesive etc it is adding at least 35 mm!

It’s pretty old but built in parts - is listed but when we went though the wall it was breeze block behind the bricks!! But would be pre 90’s. Cannot remember the brand we used, but it looked the same as this

https://www.snugufh.co.uk/water-underfloor-heating/low-profile-system/

no screed needed, there may have been some sort of Liner between the pipes and the floor boards like a foil blanket but I can’t honestly remember. The flooring had to float rather than be stuck down - but again not sure if this was due to expansion or the UFH.

We have concrete floors don't know if that makes any difference but useful info thanks

Can the fitters do a core hole to see what is there?
From 2002 I would expect/hope 150mm of insulation under the concrete slab.

Hi thanks , we dont have builders just tilers as we are only replacing the floor tiles which were cracked , and thinking of retrofitting the UFH, and heard something about disturbing radon 😳 if hikes are bored and want to keep costs low
It is assuring to know U think 2002 build should have insulation thanks