Victorian floor under floor heating

moneyspending

Renovating 1930s house. We have floor boards after carpet taken out.

Under floor boards there is 40cm empty space. Can we install underfloor heating below?

I don't understand, why is it so labour intensive as per builder? What is needed please?

spadoosh

UFH comes in two formats. A dry system and a wet system.

A dry system is an electric heating mat, youd lay it on top of floorboards and beneath whatever floor covering youre going to use.

A wet system essentially works like a radiator. Hot water pumping around your pipework.

The laying beneath floorboards comment doesnt make sense to me unless youre looking at a wet system and essentially dropping the floor height (a wet system takes up more space)?

moneyspending

Yes we definitely want wet system.

Concrete floor, insulation on top, pipes on top of insulation and then screed.

Underlay and flooring on top. Can we not fit all these in 40 cm space we have keeping floor height same as now?

FreeBear

A 1930s property is not Victorian - You are some 30 years (or more) late.


Do you intend to remove all the ground floor flooring to install concrete & UFH ?
If not, you will need to pay attention to ventilation of any remaining suspended timber floors.

Andy_L

moneyspending wrote: »

I don't understand, why is it so labour intensive as per builder? What is needed please?

moneyspending wrote: »

Concrete floor, insulation on top, pipes on top of insulation and then screed.

I suspect its laying the concrete floor that's the problem. They will need to rip out all the existing flooring. Then sort suitable foundations for the new concrete slab to be poured on, which may require digging a foot or so of earth & then lay hardcore. As its inside an existing house they can't get the big, time-saving, machinery in so will have to do much of it by hand

Alternatively they don't want to actually do the job and are quoting high to make you go somewhere else

Doozergirl

It is going to cost a fortune because you don't have a suitable substrate. You need insulation on the ground floor. You don't install underfloor heating in the fresh air underneath a wooden floor and you can't pour concrete over insulation over a wood floor so the whole lot has to come up and be relaid as concrete, filling that 40cm void back up to floor level.

Ripping up a suspended wood floor isn't a good idea at the best of times as there is no horizontal damp proof membrane in the internal walls. The house will want to breathe and start using those internal walls to breathe, appearing as damp on internal walls.

Not only that, unless you are retro-fitting the house properly with internal/external insulation, underfloor heating is not efficient as it works at lower temperatures, relying on the house to retain heat. If heat is easily able to escape (it certainly is in our 1930s house) then the house simply will not be warm enough.

I think you need to do some serious homework if you don't know the difference between a Victorian and a 1930s house, let alone how these houses behave.

I have a 1930s house with a suspended floor and have renovated houses for 20 years, to a very high standard. I am not afraid of underfloor heating but I wouldn't contemplate potentially ruining a period house at great cost and still be cold. Underfloor heating is great in the right places but not where heat isn't easily retained.

moneyspending

Yes it is 1930 not Victorian! The walls are solid, no cavity. What are my options for insulation?
I guess the answer is to put radiators in original house and UFH in extension.

vw100

moneyspending wrote: »

Yes it is 1930 not Victorian! The walls are solid, no cavity. What are my options for insulation?
I guess the answer is to put radiators in original house and UFH in extension.

Yes this would be ideal and ok

NeverTooLate

moneyspending wrote: »

Yes it is 1930 not Victorian! The walls are solid, no cavity. What are my options for insulation?
I guess the answer is to put radiators in original house and UFH in extension.

Would that still be ok if the extension bolts on to the existing rooms? We're putting an extension on the whole of the back of the house to make the existing rooms larger, so would radiators in the existing part of the rooms and UFH in the new part be warm enough?

TELLIT01

Assuming the extension has a concrete floor, there will be ventilation pipes set in to it to allow air still get through to the timber floored area. There will be the old external wall between the current timber floor and the floor of the extension. The mix of radiators and UFH should be fine.

ComicGeek

But I wouldn't put both underfloor heating and radiators in the same room, that would be difficult to control. In your case I would stick with radiators throughout and keep it simple - at least the radiators in the new extension would be smaller.