Victorian solid floor and underfloor heating

[Flipjango]

We're buying a big victorian detached house which we are fully refurbing. Part of the work is to open up the two rooms across the rear of the house to make a large kitchen, adding a small extension. Due to the layout its going to be hard to put any radiators anywhere (too many openings and doors leaving no walls to fasten them to!) so we'd like to use wet underfloor heating. The survey has turned up that one of the two rooms has a solid floor which has terracotta tiles providing the damp proofing at surface level. The other room has a suspended timber floor.

I'm looking for some advice on what we need to do with the floor in order to create space for the underfloor heating? I know we need to dig out and that its a lot of work, but the house is a wreck anyway so we're prepared for that.

On a further note, the house has solid walls and some penetrating damp problems, and we have been advised to use lime plaster and lime mortar in keeping with the original construction to ensure the walls are well ventilated so I am worried that taking out an original solid floor and installing any concrete or damp proof membrane to the sub floor will only serve to drive moisture into the walls. I've heard using limecrete instead of concrete might be help but I'm struggling to find any definitive guidance as to how to proceed?

 

[Doggit]

Hire a medium duty breaker to get the floor up, then use some of the old floor as hardcore, (you'll need a wacker plate to flatten it) then sand, a DPC membrane, and then concrete. But the next step depends on how the UFH will be done. You can lay 100mm of PIR, clip the pipes to the insulation, and then lay a screed. Or you can come up higher, and lay the Nuheat LoPro system, and then tile or wood on top.

If you haven't ended up with any wall space, then it's possible that the layout may not be the best design though. You can run a normal CH system, and add a mixer for the UFH, but it needs to be zoned so that the UFH can start the boiler a couple of hours earlier to get it up to heat for for when the rest of the house starts to warm. UFH tends to be more of a leave it on winter to spring method, as it's not so controllable if too basic.