Underfloor heating - advice needed!

[Rocketboy]

Hi all

Just looking for some advice around underfloor heating. We will be building an extension on the back of our house - 50m2. The current house is approx 40m2 with a concrete floor but if possible we would like underfloor there too in order we dont have any radiators downstairs (with the exception of the cloakroom where we will have a small towel warmer). I've had a couple of plumbers come round and have a look (neither has come back with a price yet) but both have suggested overlay panels in the current house with screed in the new part with 4 seprate zones ie hallway/cloakroom/utility, living room, dining room/study, and kitchen. From a cost perspective, would it be more cost efficient to have overlay in the old part of the house or should we just get the builder to dig it up and ask the punber to lay the same throughout the entire ground floor?? I know the deatiles are a little vague but if any of you have worked on a similar size project, could you give me an indication of the costs of materials and labour for the above.

Thank you!

 

[PhoenixServices]

Personally i would advise getting the builder to dig up the screed in the rest of the house and lay the same throughout. At least you can get the right amount of insulation underneath it then and save yourself a load of money in the long run.

 

[SimonG]

As it is for your own house then rip it up. As said you can then get the right amount of insulation underneath to give you maximum benefit. I'm not a tremendous fan of underfloor, as a lot of customers I go to that have it complain of it being too cold. Why not consider a couple of radiators to assist the underfloor, fitted with trv's they won't come on unless required but will give that bit of boost when needed.

 

[lame plumber]

need to dig up more than a couple of inches of screed to get insulation in as well, omho but your looking at quite a bit of disruption and cost in the original house

 

[Whn1]

You're best off installing a few rads in the old part and settle for underfloor in the new extension. One thing I will say about underfloor.... Don't expect miracles. I like the idea of underfloor but it's far to unresponsive for me.

 

[Rocketboy]

Thanks for all the advice guys. I think we'll rip the floor up and get new screed down. As we're going for a refrub throughout, I'm comfortable with ground floor being able to hold sufficient heat to stay warm when required (we will have new double glazing, internal doors and celotex insulated walls throughout). Can anyone advise the best products out there for underfloor including boiler with tank (mega flo I think)??

Cheers, this forum is great!

 

[lame plumber]

get quotes and advice from your installer hes on site and will know of any issues etc

 

[Destroyer2813]

Need to check water pressure and flow before heading down the unvented route, megaflow is just one brand out there there are many others that are cheaper they just have a external expansion vessel as opposed to the megaflows internal one

 

[Whn1]

Fitted loads of continental UHF systems, good quality. Also fitted a couple of polypipe ufh systems. Bothe seem ok. Continental draw up room plans for you.

 

[erpkid]

If you are digging out consider going the extra 50 mm to allow you to fit 150 mm Jablite rather than 100 mm Celotex/ Kingspan etc. Jablite does not have the same performance but with the areas you are looking at will save you a fortune on material cost.