Underfloor without floor insulation

whiskywhisky

Hi

Not sure if this thread should be here or in the Energy section?

We are starting on a double storey rear extension to our house. We have been planning this for a while and have sourced the builders/plumbers etc. Throughout our planning was that we will have a wet underfloor heating on the ground floor and radiators on the 1 st. The whole heating plumbing system/boiler is being replaced as old is ancient. The ground floor is solid concrete and first is traditional joist and house was built in 1950.

However we have been informed by the builder that it will be a lot cheaper for us to stick to radiators on the existing (old part) ground floor and put in wet underfloor heating in only the new extension on the ground floor. He mentioned that the new part will be built with adequate insulation etc to get best use of the heating. He said if we still went with the underfloor heating on the existing old part, we will be wasting energy and money to heat downwards as well.

Liaising with underfloor companies, mainly dealing with their salesmen they are saying their customer install on existing (without floor insulation) and their systems are amazing etc.

A bit confused, builder is saying to get the best out of the underfloor he will need to dig down a fair amount of the concrete and then lay insulation etc. Which is very costly, the need to dig down is only to lay insulation etc as there is plenty of head height in the room.

Please can someone advise?

System

not having insulation under the floor will mean you are basically heating up the ground with your ufh!
I once put electric underfloor in a basement conversion where the client didn't want to lift the floor slab and it took 3 weeks to get up to the minimum temperature!

whiskywhisky

Ok thanks. I was mistakenly under the impression that as heat rises it should not make a difference

DRP

whiskywhisky wrote: »

Ok thanks. I was mistakenly under the impression that as heat rises it should not make a difference

Hot AIR rises.

Hot concrete doesn't.

Skid_Solo

Have a look at Polypipe Overlay we used this in our kitchen as this was an existing concrete floor.
The insulation is in the backboard.
Its only added a total of 35mm to floor height (and that includes 10mm tiles and adhesive)
Very pleased with it keeps the kitchen at a stable temperature and has reduced the overall heating bill as it replaced 3 double radiators


Our heating engineer was so impressed he has just installed in his own house

phil24_7

If you are gutting the place, now is the time to insulate the floor and lay underfloor heating. Yes it will be expensive but it will also make the house feel a lot warmer underfoot. Do it right, do it once!

Smiley_Dan

DRP wrote: »

Hot AIR rises.

Hot concrete doesn't.

Thank you x 100,000 :beer: