First house, want to retrofit Underfloor Heating. Many Questions

[Midwest]

There are some systems davesparks, where aluminium spreader plates are use transmit the heat to the room above. No expert but as they are probably designed for rooms above the ground floor, i.e. bedrooms, guess they do not need the same amount of heat transfer as ground floor rooms. Op, the screed is heated up by the ufh and acts as the heat source. If the screed is not deep enough, and doesn't have sufficient insulation below, your wasting your time.

 

[davesparks]

There are some systems davesparks, where aluminium spreader plates are use transmit the heat to the room above. No expert but as they are probably designed for rooms above the ground floor, i.e. bedrooms, guess they do not need the same amount of heat transfer as ground floor rooms. Op, the screed is heated up by the ufh and acts as the heat source. If the screed is not deep enough, and doesn't have sufficient insulation below, your wasting your time.

That's exactly the system they used in the ground floor I mentioned, aluminium sheets which span the joists with channels in to hold the pipes. With only a few inches of fibreglass under it it was useless. What it needed was a good thick layer of celotex/kingspan.

First floor is going to be less of a problem I guess, but in a 1920s house there is likely to still be a hell of a drought under the floors to take a lot of the heat away

 

[Midwest]

First floor is going to be less of a problem I guess, but in a 1920s house there is likely to still be a hell of a drought under the floors to take a lot of the heat away

Yep seal up the floors and hang some rads IMO!

 

[rolyberkin]

I have developed houses and have used all the heating methods you describe. In the house you describe/show I would not install under floor heating either electric or water, electric is just far too expensive to run as a primary source and water is too much of a faff to retrofit. To do it properly you will have to take out all the floors downstairs to about 250mm minimum, this may sound easy but have you considered how much you have to dig out and how much waste you have to get rid of at cost? Your new house will be wrecked and look like a very grubby building site, the only way you will get the floors out is with a hydraulic kango!! you need to put in minimum of 100mm minimum insulation below, you will need to re screed floors min 50mm but probably more like 75mm (which will take an age to dry), also whatever anyone says retrofitting underfloor upstairs will not be viable so you will still need over sized rads. I cannot over estimate how bad an idea retrofitting UFH is to an old house, do not do it! If you were building a new house yes then this would be a good idea. Personally in that house I would either fit an electric boiler, air source heat pump, LPG tank and gas boiler to fit standard rads and a cylinder. If it was me with your budget I would be going with either an air source heat pump with large rads and a suitable cylinder or large LPG tank with gas boiler (You will find LPG 47kg tanks will be too expensive to use for heating and or heated water! Best of luck.

 

[PEG]

Sound advice above^ Your LPG bottles are taller than the 1m you mentioned...and you will go through them in short order.

I have 3 separate friends,whose properties are on LPG for DHW and CH,,,and their Bahco adjustable stays outside,but never gets rusty:28:

As for the retro-fit wet UFH,you WILL require at least 100mm of rigid board insulation under,and either a screed layer,for set-back,or spreader plates,for emanating your heat input.

You will also need to be anally obsessive to the point of a fanatic,in sorting ALL your other insulating requirements,drafts,and thermal sinks.

Wet UFH can be successful. But ONLY when in conjunction with attention to all the other aspects of your building.

To ignore the other thermal "leaks",can be both expensive and disappointing,and if you are tied to LPG,the first problem will far out-way the second!

...But i LOVE,"her-who-must-be-obeyed"s hat :icon6:

 

[OnlyHumanHere]

There are some systems davesparks, where aluminium spreader plates are use transmit the heat to the room above. No expert but as they are probably designed for rooms above the ground floor, i.e. bedrooms, guess they do not need the same amount of heat transfer as ground floor rooms. Op, the screed is heated up by the ufh and acts as the heat source. If the screed is not deep enough, and doesn't have sufficient insulation below, your wasting your time.

With with a floating floor, I'm told by many that there's absolutely no requirement for screed.

https://www.youtube.com/watch?v=1BpH65IsNy0

 

[OnlyHumanHere]

Sound advice above^ Your LPG bottles are taller than the 1m you mentioned...and you will go through them in short order.

I have 3 separate friends,whose properties are on LPG for DHW and CH,,,and their Bahco adjustable stays outside,but never gets rusty:28:

As for the retro-fit wet UFH,you WILL require at least 100mm of rigid board insulation under,and either a screed layer,for set-back,or spreader plates,for emanating your heat input.

You will also need to be anally obsessive to the point of a fanatic,in sorting ALL your other insulating requirements,drafts,and thermal sinks.

Wet UFH can be successful. But ONLY when in conjunction with attention to all the other aspects of your building.

To ignore the other thermal "leaks",can be both expensive and disappointing,and if you are tied to LPG,the first problem will far out-way the second!

...But i LOVE,"her-who-must-be-obeyed"s hat :icon6:

Sound advice.

I guess what I need to do is to get a few specialists in and actually go from there.

I do intent to fit a multifuel burner in the living room, which should make things toasty.

Haha, she's a big fan of hats.

 

[telectrix]

Sound advice.

I guess what I need to do is to get a few specialists in and actually go from there.

I do intent to fit a multifuel burner in the living room, which should make things toasty.

Haha, she's a big fan of hats.

IMO, that's a better option. get a multi-fuel jobby with back boiler, then run rads off it.

 

[Midwest]

Sound advice.

I guess what I need to do is to get a few specialists in and actually go from there.

Think that's a good idea, and with due respect to my learned colleagues here, getting processional advice on for heating & hot water, in your particular situation, is perhaps the best way forward.

 

[OnlyHumanHere]

IMO, that's a better option. get a multi-fuel jobby with back boiler, then run rads off it.

Sadly we don't plan to use it as a daily...more of a cetre piece when we have guests over.

I don't know what it is, i just really hate rediators, they take up space, are complete eyesores and far from efficient. This is why it's hard for me to throw my plans for ufh out and fit radiators. My wife's from South Korea, where radiators just don't exist, when she first came to the uk 7 years ago, she didn't realise they were actually used for anything more than vintage designing, lol. Visiting her family so many times, i've been spoiled experiencing really efficient ufh, it's so nice on the feet.