Underfloor heating in a new extension

[RonBowater]

Hi .. I'm planning a 4.5m x 3.5m 'family room' extension to our house which I want to be as comfortable as possible in the winter months. Our house is standard oil-fired with piped hot water (15mm piping) to radiators in most rooms. I can extend the piping to the new extension fairly easily and install a couple of radiators to be consistent with the rest of the house. However, I am tempted to install some underfloor heating (under good quality oak flooring) to keep the room as warm as possible at floor level. The oil boiler is quite a distance from the new extension so it is not really possible to install a separate piping circuit from the boiler for a hot water UFH. This left me wondering whether it makes sense to go for an electric system and if so, should I make this in addition to the standard radiator system or will it be sufficient by itself. If an electric system is recommended, can anyone point me to any particular manufacturor and/or system please ? Are there any considerations as to the floor construction for an electric UFH (e.g. insualation, screed thickness etc) ? I assume that electric UFH usually comes with a temperature/time controller but can it just be connected into a spur on the standard 13 amp ring main or is a separate fused curcuit required ?
How reliable are these underfloor electric blankets ?

Thanks
Ron

 

[mointainwalker]

You need to consider your flooring at the same time as you think about the UFH. You speak of "good-quality oak " so I'm assuming you mean thick, solid oak ?

Do some research as wood is a good insulator and there maybe a max recommended thickness ( 15 mm maybe ? ) for an efficient system.

 

[dextrous]

To be honest, I haven't come across electric underfloor heating that warms a room particularly well, so I would err on the side of caution and install radiators as well.

I am a bit confused anyway - you say that you can easily extend the current wet system to add rads, which would seem to imply that you have access to the main flow and return pipes. As this is basically all that is needed to feed the manifold/pump, apart from cable runs etc, it is difficult to fully understand what the issues are with installing a wet system.

Finally, as this is a new extention, it seems fair to assume that the subfloor insulation will be acceptable for wet or electric. Wet usually require about 60mm screed, whereas electric (to my limited knowledge) requires none. I assume that you have googled about this and read manufacturers installation methods.