UFH Construction of floor choice

[Strangey71]

Hi

I have a question I am renovating and extending a detached 1950s build. I am trying to future proof as much as possible, my question is, I have 6 rooms downstairs on completed build but as they are now the void space under the floor from room to room varies incredibly from 3.5" joists with barely 4"void to 3.5"joists with 24" void in places. I intend to install wet under floor heating throughout,  would I you relay the whole ground floor with new concrete, insulation and screed? would this be a better or more cost effective in the long run.

[JohnMo]

I would add 200mm PIR insulation, UFH pipes attached to that and then the concrete slab.

 

Someone will come along and say if you cannot do that. 

[Dave Jones]

Is it bare soil or stoned already ?

 

DPM membrane ?

 

normal practice is 100mm hardcore whacked, sand blinded, DPM lapped up to house DPC, insulation min 150, screed 75mm