First house, want to retrofit Underfloor Heating. Many Questions

[rolyberkin]

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

UFH is good when you are well insulated from below and are warming a large slab of screed to work as a thermal store at low heat, it is good, I have two rooms where I have it.

I haven't used this stuff but it will add a significant depth to your existing floors, this will have to go all through the house or you will have steps to trip up and down. Self-leveling compound isn't really self-leveling, you will have to get someone in to do it properly it has to be levelled properly using a float, it is expensive to buy and to level.

To fit this stuff properly you will have to take off all your skirting boards and architrave and refit all of your doors. there is not much of a thermal store in a few cm's of compound so in effect you will be using it like a radiator in any case. To fit a wet central heating system a plumber will be in and out in a couple of days, job done, nice and toasty!

 

[Midwest]

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.

We have a multi fuel burner. Small one, but sufficient to heat our moderately sized living room. We turn the CH down at night (or I do) and just use the burner to keep us nice & warm. Again, your have to think of your heating design. Any multi fuel burner over 5kw needs some ventilation.

As stated several times here, wet UFH in an existing property will require considerable disruption & expense. It's your money, but I'm sure that can easily be spent on the refurbishment of your new acquisition. Create a spending plan for all the other projects you will have on your refurbishment, and see what penny's you have left.

Modern radiators are more efficient these days, and include some attractive modern designs, if that's your style.

 

[davesparks]

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

They are right, there is no requirement to screed over the pipes in those systems. But to get a system which works well you will want to bury the pipes in screed with a thick insulation layer under the pipes

 

[sean_ork]

No screed = no thermal mass = fast heat up + fast cool down = bad

Screed or concrete slab with wet UFH embedded with + 250mm insulation below + 50mm perimeter = slow heat up + slow cool down = very good

Please don't consider electric heating unless you massively insulate the entire house - leccy heating is popular with landlords as its cheapish and quick to install with minimal disruption - but its not the landlord that will be paying the ongoing bills.

 

[davesparks]

No screed = no thermal mass = fast heat up + fast cool down = bad

Screed or concrete slab with wet UFH embedded with + 250mm insulation below + 50mm perimeter = slow heat up + slow cool down = very good

Please don't consider electric heating unless you massively insulate the entire house - leccy heating is popular with landlords as its cheapish and quick to install with minimal disruption - but its not the landlord that will be paying the ongoing bills.

Plus electric heating has its active elements under the floor which can go faulty and require a massive effort to dig it up to fix it.
Wet systems only have a pipe under the floor with all the active components at the manifold, much easier to fix if it hoes wrong

 

[Midwest]

Don't think we are going to convince the OP against ufh. Think he's been advised as best as we can.

 

[sean_ork]

Don't think we are going to convince the OP against ufh. Think he's been advised as best as we can.

Nothing wrong with UFH, as long as its the right type, and done as a combined job of installing lots and lots of insulation, and a fair bit of digging down.

 

[Midwest]

Nothing wrong with UFH, as long as its the right type, and done as a combined job of installing lots and lots of insulation, and a fair bit of digging down.

Not disagreeing, if you've read my other posts. Just not realistically achievable with this property.

 

[sean_ork]

Not disagreeing, if you've read my other posts. Just not realistically achievable with this property.

There's nothing structurally preventing proper wet UFH being installed, thats just money, effort and time - perhaps the disruption and need to have it all in with 2 months makes doing the job properly unrealistic.

 

[Midwest]

There's nothing structurally preventing proper wet UFH being installed, thats just money, effort and time - perhaps the disruption and need to have it all in with 2 months makes doing the job properly unrealistic.

Give me strength!

 

[davesparks]

There's nothing structurally preventing proper wet UFH being installed, thats just money, effort and time - perhaps the disruption and need to have it all in with 2 months makes doing the job properly unrealistic.

How do you know that there's nothing structurally preventing it? With the age of the building there may be very limited foundations which may then require underpinning before the floors can be dug out far enough to get a concrete slab cast to then get a thick enough insulation layer down.

 

[sean_ork]

How do you know that there's nothing structurally preventing it? With the age of the building there may be very limited foundations which may then require underpinning before the floors can be dug out far enough to get a concrete slab cast to then get a thick enough insulation layer down.

My point is that it's a fairly normal house, its structurally indentical to 100,000s of other, there's nothing to stop UFH being installed, it almost certainly will have shallow founds - but that's nothing that hasn't been resolved before, just needs time effort and disruption - MW implied that UFH just wasn't "realistically achievable" which certainly isn't right, but will need a change of view by the home owner.

Any type of UFH, or any other form of space heating with no associated insulation and air tightness work is pointless, unless they like big bills.

I'm hoping the OP extends his timescales and does the job properly - remembering that you only pay once to do the job properly, you'll be forever paying high energy bills if you install a thermally compromised solution.

 

[telectrix]

i heard today that they're scrapping the original Enterprise 1701. dylithium crystals now on ebay . power and heat for 300 years.:grinningelf:

 

[davesparks]

My point is that it's a fairly normal house, its structurally indentical to 100,000s of other,

How can you tell that? As far as I can tell it's a 1920's built converted schoolhouse with a thatched roof in Wiltshire.
So it is not going to be like a fairly normal house as most normal houses weren't built as schools and thatch roofs are not all that common except in isolat dare as of the country.

 

[sean_ork]

I can tell as much as you can, it is not a unique structure - it is suitable for retro fitting UFH of the type I have described.

 

[Midwest]

MW implied that UFH just wasn't "realistically achievable" which certainly isn't right, but will need a change of view by the home owner.

I'm hoping the OP extends his timescales and does the job properly - remembering that you only pay once to do the job properly, you'll be forever paying high energy bills if you install a thermally compromised solution.

I do not have a negative view of the system, I would consider it's installation in a property of my own. But I wouldn't consider it, if I had to pay to remove an existing screed floor, pay for the accumulated waste to be disposed and then pay for someone to reinstate the finished floor. As someone else mentioned, there is also the ancillary cost of reinstating wood finishes etc. I'm guessing at £800-900 per average room? That's why I said, in my opinion, it was not realistically achievable.

In a property of this age, the existing finished floor and sub floor, may well be in need of renovation. Then it might be viable.

It is up to the OP how he spends his money, but he does mention at least once, he has financial limitations. Anything is achievable, as long as you have deep pockets.

 

[sean_ork]

It is up to the OP how he spends his money, but he does mention at least once, he has financial limitations. Anything is achievable, as long as you have deep pockets.

He said he's got 10k to spend on boiler, UFH and laminate - that's fairly healthy just for that element of the works, obvioulsy that will change if he does the job properly.

He's also said that this will be their forever home - that's a signicant statement - they will be paying energy bills forever.

What's the point of throwing in a cheap to install, cripplingly expensive to run heating system now - you only pay for a proper job the once, you'll be paying energy bills forever.

You are correct, it is the OPs money not ours to spend for him.

 

[sean_ork]

...well beyond my expertise.

What's the EPC rating of your new home ?

 

[Midwest]

He said he's got 10k to spend on boiler, UFH and laminate - that's fairly healthy just for that element of the works, obvioulsy that will change if he does the job properly.

He's also said that this will be their forever home - that's a signicant statement - they will be paying energy bills forever.

What's the point of throwing in a cheap to install, cripplingly expensive to run heating system now - you only pay for a proper job the once, you'll be paying energy bills forever.

You are correct, it is the OPs money not ours to spend for him.

By my calculations and guesstimate, that's about 5k on digging up & putting back the floor.

 

[sean_ork]

By my calculations and guesstimate, that's about 5k on digging up & putting back the floor.

This is rather pointless, the OP has stated he's happy to do some relatively unskilled tasks - and its never been suggested that the system I've mentioned would fit within his stated budget - do a job once and do it right, its their forever home, that's my point.

 

[UNG]

He said he's got 10k to spend on boiler, UFH and laminate - that's fairly healthy just for that element of the works, obvioulsy that will change if he does the job properly.

He's also said that this will be their forever home - that's a signicant statement - they will be paying energy bills forever.

What's the point of throwing in a cheap to install, cripplingly expensive to run heating system now - you only pay for a proper job the once, you'll be paying energy bills forever.

You are correct, it is the OPs money not ours to spend for him.

So what budget will he need for the rest of the work needed even an expensive installation could have high running costs


The problem as I see it is that little thought has been put into the on going costs of running the system, this really needs a bit more than beer mat planning and a wet finger in the air to find a cost effective solution to provide heating and hot water at an affordable cost.
I've seen it many times where people have jumped in with both feet only to find their chosen system is too expensive to run with no access to mains gas and the possible planning issues with utilising alternative energy sources this property is going to be an interesting design challenge for someone

 

[sean_ork]

So what budget will he need for the rest of the work needed even an expensive installation could have high running costs


The problem as I see it is that little thought has been put into the on going costs of running the system, this really needs a bit more than beer mat planning and a wet finger in the air to find a cost effective solution to provide heating and hot water at an affordable cost.
I've seen it many times where people have jumped in with both feet only to find their chosen system is too expensive to run with no access to mains gas and the possible planning issues with utilising alternative energy sources this property is going to be an interesting design challenge for someone

I've got no idea how much extra he will have to spend, maybe ask MW for one of his guesstimates.

I completely agree with the rest of your comments, thats the same point ive been making - its often a false ecconomy to install a heating system, with little regards to insulation/thermal bridges/air tightness. Competent spending on these will negate the need for any space heating, but that certainly will be a challenge in that building.

No access to mains gas is currently advantageous price wise for those who use LPG/Sec28, but who knows what it will cost in x years.

 

[UNG]

By my calculations and guesstimate, that's about 5k on digging up & putting back the floor.

I wouldn't like to guess what it would cost there are too many variables not least the possible structural issues of digging the floor out which would need to be assessed.
Looking at the location with double yellow lines on the road and what looks to be very limited or no parking there may be issues locating skips to remove spoil and taking delivery of concrete and other materials which could significantly affect costs if this has to be done out of normal hours

 

[OnlyHumanHere]

There's nothing structurally preventing proper wet UFH being installed, thats just money, effort and time - perhaps the disruption and need to have it all in with 2 months makes doing the job properly unrealistic.

There's no requirement to live in it until the job is done. We currently live in military married quarters so there's no rush...i'd just rather it all done in about 2 months.

 

[OnlyHumanHere]

How do you know that there's nothing structurally preventing it? With the age of the building there may be very limited foundations which may then require underpinning before the floors can be dug out far enough to get a concrete slab cast to then get a thick enough insulation layer down.

I really couldn't disagree enough...you don't need thick insulation underneath the UFH...you need the heat to be reflected up...not absorbed down...that's just wasteful. Speaking to professionals, i could just layer the ufh on the current floor boards if i'm prepared to loose an inch or two of the room height.

 

[OnlyHumanHere]

How can you tell that? As far as I can tell it's a 1920's built converted schoolhouse with a thatched roof in Wiltshire.
So it is not going to be like a fairly normal house as most normal houses weren't built as schools and thatch roofs are not all that common except in isolat dare as of the country.

It's not the thatched roof one...it's the white house.

 

[OnlyHumanHere]

Firstly I'd like to thank everyone for their comments, it's been good to see insight from both sides of the fence.

Having spoken with some specialists in Salsibury (though since we haven't got the keys yet, we haven't been able to get the some proper specialist advice)...I've told my wife to scrap the idea of putting ufh upstairs...since upstairs will be the guest room and my daughters room...there's no much need for the hassle....we'll just buy a heated play matt for our daughter it really matters. Like this but bigger (not sure why the photo is so big, apologies for that.

Like I said, there's no rush to move into the house, however I'm not a fan of tea breaks when a job needs doing so I expect things to be done in a timely manner. The beauty of being in the military is that I have a large supply of man power I can utilize for the price of a few crates of carling (they really aren't picky), which is nice.

This idea of needing to dig down to china to make sure i have miles of insulation under the UFH just isn't required...I'm not needing to warm up the ground surface, I'm wanting the heat to be reflected upwards....the beauty of floating floor on top of ufh IS that it heats up quickly and cools down quickly imo. If the room is cold, I want it to heat up quickly, there's little draft in the house so there's no worry of heat escaping...there's not even a chimney in the house which is the main reason why old houses are normally drafty. I plan to kit the house out with google nest or another smart thermostat which'll will help with costs as it'll know when we're out of the house or know our habits for keeping the place warm.

 

[UNG]

I really couldn't disagree enough...you don't need thick insulation underneath the UFH...you need the heat to be reflected up...not absorbed down...that's just wasteful.

So how do you propose to install it then without creating an inefficient expensive to use heating system. The biggest issue with UFH are the losses into the slab / floor below it

Speaking to profressionals, i could just layer the ufh on the current floor boards if i'm prepared to loose an inch or two of the room height.

So why come on here for advice and then go on to imply something that may offend those professionals on here, these profressionals you have spoken to are obviously up to speed with properties like yours and can offer a turnkey solution for you property. I have no doubt you could lay it on the current floor boards with a loss of room height but have they given any indication as to whether this compromises the efficiency of the system

 

[davesparks]

I really couldn't disagree enough...you don't need thick insulation underneath the UFH...you need the heat to be reflected up...not absorbed down...that's just wasteful. Speaking to professionals, i could just layer the ufh on the current floor boards if i'm prepared to loose an inch or two of the room height.

Professional what? Salesmen, installers or impartial third party engineers?
Have they quoted any actual figures for efficiency and heat losses for the different options?



You've got a lot of relatively impartial professionals on here advising you that you do need good insulation, so what makes your other professionals better than us?

 

[sean_ork]

I really couldn't disagree enough...you don't need thick insulation underneath the UFH...you need the heat to be reflected up...not absorbed down...that's just wasteful. Speaking to professionals, i could just layer the ufh on the current floor boards if i'm prepared to loose an inch or two of the room height.

I'm not sure what you currently do for a living, but I really do hope its nothing technical - your understanding of how insulation works is completely incorrect - perhaps you've been sold that nonsense by a salesman.

You could just lay insulation on top of your current FFL, but using your logic you'd not need any insulation, you'd just need to reflect it upwards.

Stop listening to sales folks, try talking to other who've actually got to live such a system - if you like throwing money away the carry on there Captain Mannering.

Your daughter won't be happy with just a few 100 watts of heated mat to keep her warm.


What's the EPC rating of the house ?

 

[sean_ork]

This idea of needing to dig down to china to make sure i have miles of insulation under the UFH just isn't required...I'm not needing to warm up the ground surface, I'm wanting the heat to be reflected upwards....the beauty of floating floor on top of ufh IS that it heats up quickly and cools down quickly imo.

Just out of curiosity, what have you read, or been told, that has made you form this opinion ?

 

[Midwest]

I think this thread is going round in circles. Seems we're back at the beginning again.

 

[sean_ork]

I think this thread is going round in circles. Seems we're back at the beginning again.

It's going backwards

 

[OnlyHumanHere]

It's going backwards

Agreed, so let's move forward.

My biggest issue still hasn't been resolved.

Let's ignore the pros and cons of UFH and whether it'll be worth it.

Let's say all of a sudden it is worth it and it's a great idea that'll be easy and simple.

My next concern is the boiler. Since I don't have space for a big tank in the garden for LPG, the cooker is LPG supplied via bottles stored on the side of the house..the bottles are only domestic, maybe about 19kg size.

How much and how long does it normally take to fit a combi boiler?

 

[UNG]

Firstly I'd like to thank everyone for their comments, it's been good to see insight from both sides of the fence.

Not sure what fence you are on about here

Having spoken with some specialists in Salsibury (though since we haven't got the keys yet, we haven't been able to get the some proper specialist advice)...I've told my wife to scrap the idea of putting ufh upstairs...since upstairs will be the guest room and my daughters room...there's no much need for the hassle....we'll just buy a heated play matt for our daughter it really matters. Like this but bigger (not sure why the photo is so big, apologies for that.

I am beginning to think this thread is the work of a troll as no one who is serious would consider one or more of these mats as an alternative to a properly designed and installed heating system, reading the spec alone worries me that you would even consider one or more of these mats for a child's room who will more than likely unsupervised most of the time, a surface temp of 40 - 60°C has the potential for burns or even causing a fire. I would have serious thoughts about your choice of specialist if they are recommending these mats

Like I said, there's no rush to move into the house, however I'm not a fan of tea breaks when a job needs doing so I expect things to be done in a timely manner. The beauty of being in the military is that I have a large supply of man power I can utilize for the price of a few crates of carling (they really aren't picky), which is nice.

I find some of your comments in this thread so far are very disparaging and insulting I think I'd prefer a tea drinking professional than a bunch of p****d up squaddies installing my heating system you what find out they are not too picky how good the finished system is

This idea of needing to dig down to china to make sure i have miles of insulation under the UFH just isn't required...I'm not needing to warm up the ground surface, I'm wanting the heat to be reflected upwards....the beauty of floating floor on top of ufh IS that it heats up quickly and cools down quickly imo. If the room is cold, I want it to heat up quickly, there's little draft in the house so there's no worry of heat escaping...there's not even a chimney in the house which is the main reason why old houses are normally drafty. I plan to kit the house out with google nest or another smart thermostat which'll will help with costs as it'll know when we're out of the house or know our habits for keeping the place warm.

I think you need to go and do some research about what insulation actually does. Once you have done that then you may want to research thermal effects and energy usage. Your comments show you have little knowledge on the subject and if you are relying on the specialists you have spoken to then you appear very very badly advised

I'm not sure what you currently do for a living, but I really do hope its nothing technical - your understanding of how insulation works is completely incorrect - perhaps you've been sold that nonsense by a salesman.

You could just lay insulation on top of your current FFL, but using your logic you'd not need any insulation, you'd just need to reflect it upwards.

Stop listening to sales folks, try talking to other who've actually got to live such a system - if you like throwing money away the carry on there Captain Mannering.

Your daughter won't be happy with just a few 100 watts of heated mat to keep her warm.


What's the EPC rating of the house ?

You are close although I think you may have the rank wrong

 

[davesparks]

Agreed, so let's move forward.

My biggest issue still hasn't been resolved.

Let's ignore the pros and cons of UFH and whether it'll be worth it.

Let's say all of a sudden it is worth it and it's a great idea that'll be easy and simple.

My next concern is the boiler. Since I don't have space for a big tank in the garden for LPG, the cooker is LPG supplied via bottles stored on the side of the house..the bottles are only domestic, maybe about 19kg size.

How much and how long does it normally take to fit a combi boiler?

Fitting the boiler itself takes maybe an hour, but then you have install all of the pipework to it, wire it, flush, fill, test, commission etc etc etc.

But if you can get a proper gas tank installed then you won't be wanting a gas boiler, you'll be changing bottles every other day!

 

[OnlyHumanHere]

Fitting the boiler itself takes maybe an hour, but then you have install all of the pipework to it, wire it, flush, fill, test, commission etc etc etc.

But if you can get a proper gas tank installed then you won't be wanting a gas boiler, you'll be changing bottles every other day!

Yea, I'm swaying to the idea of spending a bit of extra and getting a an electric boiler with indirect cylinder and scrapping the immersion heater.


I'm guessing that it shouldn't be too hard to replace the immersion heater since the piping will be in that area anyway.

I'm currently paying well over the odds in my current residence for gas and electric so no matter what I do I'll definitely be saving money.

 

[davesparks]

Electric Combis have come leaps and bounds in the last few years...

I'm guessing that it shouldn't be too hard to replace the immersion heater with a combi since most/all the piping will be in that area anyway.

Have they? What leaps and bounds would they be?

Guess again! The current hot water cylinder will be fed from a header tank above at low pressure with low pressure outgoing hot water. The combi will need a cold main and has a higher pressure hot water outlet, plus a relatively large electricity supply running to it.

 

[sean_ork]

Third time lucky maybe .......

What's the EPC rating of the house ?

 

[OnlyHumanHere]

Have they? What leaps and bounds would they be?

Guess again! The current hot water cylinder will be fed from a header tank above at low pressure with low pressure outgoing hot water. The combi will need a cold main and has a higher pressure hot water outlet, plus a relatively large electricity supply running to it.

ignore that comment, I'm an idiot. Just spoke to the electric heating company, they've recommended a comet 12kw boiler with 180L indirect cylinder.

looks like it'll do the job Indirect Cylinder Packages - The Electric Heating Company