Emergency Insulation question

marielle

Hi all, i desperately need help deciding on the insulation that is going to go this week in my new build. A lot of decisions have already been made but i find myself very uncomfortable with the choices that my builder has made and I simply must get other opinions. I have looked at countless web sites and forums and at this stage I am more confused than ever!!!
Here is the situation :
House is up. Windows in, roof on.
Cavity insulation was a gray polystirene lookalike about 60 mm thick held by pegs onto the wall.
Heating system is air to water heat pump backed up by a gas boiler.
UFH heating throughout. Downstairs, Kingspan board under screed which is already poured, upstairs nothing but screed and mesh on concrete slabs. no insulation on floor.
Heat recovery system is also being installed so an important consideration is airtightness of the building.
My builder has it in his head that multifoils are the business and wants to fit that and only that for roof insulation . For the walls, we will use insulated boards to dry line external walls. He was going to use thinner but i insisted on 50mm. He is considering putting some insulation underneath the concrete slabs on the ceilings of the rooms downstairs as well.
I have been reading terrible things about foils and them not meeting regs. I am not even sure they are suitable for an airtight building.
The way I picture it, i will have nothing between the bitter outside cold and my rooms but slates and the membrane, some air, then a sheet of foil and a 12.5mm slab. This does not fill me with confidence to say the least....
The house is a one and a half storey. All upstairs windows are velux, not much attic space which will probably only be used to house the heat recovery unit.
Please please someone give me options!!! I want to be able to go to my builder with some answers. Should foils be used at all? Are they suitable for creating an airtight house? What are the options to achieve this?
As for the roof insulation, should I use boards between rafters or some kind of stuffed material? Is there a miracle product that would fit my requirements?
What about the walls? Drylining with a Kinspan like product seems my only option as this stage. Will 50mm be enough? Should a gap be left behind the board when fitting it? I also read about condensation issues... I will be using a heat recovery system so does that mean that moisture should not be a problem in my case? what about the cold bridging at the base and top of the walls? How can that be addressed?
I don't mind spending a good bit of money on insulation but what i don't want is to end up with a cold drafty house with a useless heat recovery system just because my builder bought something shiny at the register! He is old school so i don't know why he loves this stuff so much but there is simply too much at stake for me here to take his word for it.
HELP!!!!!

sinnerboy

first thing - log on to SEI website and find a good air tightness tester now .

you need air tightness of 5 air changes max for HRV to work

a good tester will visit before plastering and give pointers to the builder on how to achieve the required result

expect to pay about €1k

secondly , under no circumstances use multi foils - they have no credible tests to prove their performance claims .

check that your roof membrane ( below tiles ) is breathable . i.e speak to product supplier of material . you may or may not need to ventilate BELOW the felt depending on this answer .

then cut kinsgpan / xtratherm type boards betwween the rafters , to the max depth possible , still leaving a 50 space below the felt .

then run min 50 thick kinsgpan / xtratherm below the rafters . foil tape the joints . foil tape to velux frames and any other pentartions - such as vent pipes .

then run foilbacked plasterboard over and skim . dont use recessed lighting

thirdly walls . batten out with timber 50 x 25 . run battens continous at skirting level and at ceiling level . cables and pipes go in 25 batten cavity . run 50 kinsgpan / xtratherm over . foil tape joints .

if internal space allows , run another 50 kinsgpan / xtratherm again and foil tape joints . foil tape to window frames ,door frames and around any other wall penetrations then run foilbacked plasterboard over and skim .

use 25 kinsgpan / xtratherm plasterboard to window / door jambs .

the first floor is a big concern - UFH pipes must have insulation below - you will just be heating your pre cast floor slabs .................

have a scrap with builder if you have to , you will be there long after he is gone

bauderline

Folks,

I have hired a BER Assessor to provide FULL insulation specifications for me backed up with the calculations that I can provide in black and white to my builder. Cost was 100 euro, I would say the best 100 euro I will ever spend !

He is also going to work with me during the course of construction to advise on the various options for heating, water, ventilation, air tightness with a view to attaining the best possible rating for the house on completion. That will cost around another 400 euro but will include the final cert.

If you are going to build your own house get a professional in to draw up a formal spec for insulation and your energy efficiency rating as this stuff is now way too important to leave to guesswork.....

Sorry for hijack... but worth saying....

baud.

sydthebeat

have you no professional engaged to inspect or supervise this build?

Firstly, he should not have incorporated 60mm polystyrene into the walls. That hasnt been acceptable for 5 years now. Its a good job you demanded 50mm insulated plasterboard, this may bring you up to minimum regulations. A quick calculation of 60 EPS and 47.5mm insulated plasterboard in a trad cavity wall gives a u value of 0.26.. .thats just below the min of 0.27....
not exactly optimal when you are installing air to water HP and UFH.

The HRV system is a must.

I completely agree with sinnerboy re multifoils, they are unprovable as an insulator... and they are an expensive vapour check membrane.

I wouldnt bother insulating the ceiling downstairs since there is no insulation below the screen on the first floor.

You need to give more info as to the exact make up of the ground floor construction.


But most important to guarantee the best performance at this stage is to hire a competent professional to inspect this 'old school' guys work......

Lynch32

bauderline wrote: »

Folks,

I have hired a BER Assessor to provide FULL insulation specifications for me backed up with the calculations that I can provide in black and white to my builder. Cost was 100 euro, I would say the best 100 euro I will ever spend !

Hi Bauderline,
this is my problem at the moment, trying to figure out an insulation plan. My brain is fried at the moment from reading all the threads and i am none the wiser (well maybe a little wiser).
Would it be possible for you to PM me the BER accessor's details so i could get him to do the same for me. I would love an expert to tell me - this is the best solution for your type of house. I am terrified of getting it wrong and everybody i talk to seems to have very different opinions.

Many thanks
Lynch

fitzie79

bauderline wrote: »

Folks,

If you are going to build your own house get a professional in to draw up a formal spec for insulation and your energy efficiency rating as this stuff is now way too important to leave to guesswork.....

Sorry for hijack... but worth saying....

baud.

Hi bauderline, could you pm anyone professionals who could help with the insulation in the cork region?

ircoha

sinnerboy wrote: »

first thing - log on to SEI website and find a good air tightness tester now .

you need air tightness of 5 air changes max for HRV to work

a good tester will visit before plastering and give pointers to the builder on how to achieve the required result

expect to pay about €1k

secondly , under no circumstances use multi foils - they have no credible tests to prove their performance claims .

check that your roof membrane ( below tiles ) is breathable . i.e speak to product supplier of material . you may or may not need to ventilate BELOW the felt depending on this answer .

then cut kinsgpan / xtratherm type boards betwween the rafters , to the max depth possible , still leaving a 50 space below the felt .

then run min 50 thick kinsgpan / xtratherm below the rafters . foil tape the joints . foil tape to velux frames and any other pentartions - such as vent pipes .

then run foilbacked plasterboard over and skim . dont use recessed lighting

thirdly walls . batten out with timber 50 x 25 . run battens continous at skirting level and at ceiling level . cables and pipes go in 25 batten cavity . run 50 kinsgpan / xtratherm over . foil tape joints .

if internal space allows , run another 50 kinsgpan / xtratherm again and foil tape joints . foil tape to window frames ,door frames and around any other wall penetrations then run foilbacked plasterboard over and skim .

use 25 kinsgpan / xtratherm plasterboard to window / door jambs .

the first floor is a big concern - UFH pipes must have insulation below - you will just be heating your pre cast floor slabs .................

have a scrap with builder if you have to , you will be there long after he is gone

Sinnerboy: Comprehensive spec indeed.

Agree 100% re multifoils: totally discredited at this point.

A few questions if I may.

If using a breathable felt such as tyvek suproplus
http://www2.dupont.com/Tyvek_Construction/en_IE/products/roofing_products/roofing_products2/suproplus.html

which allows for an unventilated roof, why do you still suggest the 2" gap?.

In relation to the internal walls is the ideal sandwich
25 plus 50 plus 50 plus 12.5?

How is the foil backed PB fixed: long screws to 50 by 25?

In your design, what do you use to seal off the cavity around the different opes?

Finally, is the 25mm around the doors and windows fitted after the frames are fitted and thus leaving a much reduced window /door frame visible?
Thanks.

pbergin

I think I changed my mind 10 times in the last 24 hours what insulation I will use. I ended up with 100mm extratherm in the floor and 100mm in the cavity, not 100% sure what I will put in the roof, was seriously considering the foil I thought it sounds simple fit and also easier to fit correctly, I am nervious about cutting insulation boards between the rafters, I think it is too easy to leave air gaps either side of the board.

archtech

pbergin wrote: »

not 100% sure what I will put in the roof, was seriously considering the foil I thought it sounds simple fit and also easier to fit correctly:

Foil doesn't have Agreement Board Certification, nor can it achieve it under the current criteria for assessing insulation.

sinnerboy

ircoha wrote: »

Sinnerboy: Comprehensive spec indeed.

Agree 100% re multifoils: totally discredited at this point.

A few questions if I may.

If using a breathable felt such as tyvek suproplus
http://www2.dupont.com/Tyvek_Construction/en_IE/products/roofing_products/roofing_products2/suproplus.html

which allows for an unventilated roof, why do you still suggest the 2" gap?.

In relation to the internal walls is the ideal sandwich
25 plus 50 plus 50 plus 12.5?

How is the foil backed PB fixed: long screws to 50 by 25?

In your design, what do you use to seal off the cavity around the different opes?

Finally, is the 25mm around the doors and windows fitted after the frames are fitted and thus leaving a much reduced window /door frame visible?
Thanks.

50mm vent gap - in this case is a "belt and braces" approach . IF the OP is CERTAIN that an agrement certified breathable felt , such as you named , is used AND is certain that tiles are fixed on battens and counterbattens to give a 50mm vent space OVER that felt .... than 50mm vent space under would not be needed . I am guessing the OP will have difficulty establishing all this for certain and so am recommending the 50mm vent gap below the felt .

I am not sure what you asking me about internal walls - if you means internal faces of external walls - I will share my thoughts on the spec I advised the OP as follows

1. aiming to get max u value at optimum insulation thickness . PU's can't be beaten here .
2. OP states a desire for min 50 pu - I am suggesting 100 - but in two 50 layers because elecs usually make mess of deep insulation layers

So 50 wide x 25 deep battens are fixed to the blockwork . Important to run continuous battens horizontally at top ( ceiling ) level and bottom (skirting) level to help restrict air flow to the battens cavity . Battens cavity is where elecs should be - it is dangerous to allow them overheat by being sandwiched in insulation

First layer of pu next , foil faced both side is screw fixed to battens . Foil taping to board joints assists vapour control . If OP budget can't stretch any more - foil backed plasterboard is screw fixed through pu into battens now .
( Alternatively polythene vapour check and regular plaster board ) .

If the OP budget can take it and if internal room sizes are not too tight a second layer of pu , with board joints staggered relative to first layer , goes on next . Long screws through pu into battens . Instruct electrician to cut only this second layer for elec points - i.e first pu layer continues unbroken behind elec back boxes . Heating pipes ( unlike cables can happily be sandwiched between the pu layers , by cutting a chase in the second pu layer . ( OP has ufh so this does not arise ) . Again second pu layer is foiltaped at joints - to further enhance vapour resistance . Foilbacked plasterboard next ( fixed with long , drilled screw fixing into battens ) .

Composite plasterboards are often used , but I like the opportunity to tape the pu board joints by using pu separate to plasterboard .

When you ask how to seal off cavity around opes I take it you mean the battens cavity . Ensure that the battens , (required for board fixing any way ) run unbroken around the opes .

Lastly insulated jambs around openings . Frames are typically between 44 - 50mm wide and located 10mm proud of the opening . So block face to frame edge is approx 54-60mm . Here I would dab on the ( 25+12) composite board , which will leave 13-20 mm visible frame margin . I like to make the inner block opening 20mm larger than outer block opening to give a bigger margin ..

I hope understood and answered your queries

sinnerboy

pbergin wrote: »

I think I changed my mind 10 times in the last 24 hours what insulation I will use. I ended up with 100mm extratherm in the floor and 100mm in the cavity, not 100% sure what I will put in the roof, was seriously considering the foil I thought it sounds simple fit and also easier to fit correctly, I am nervious about cutting insulation boards between the rafters, I think it is too easy to leave air gaps either side of the board.

forget the foil

PU mm for mm out performs quilts by a factor of 2 ( approx ) . HOWEVER neatly cutting them between rafters is difficult ( do-able with skilled workforce however ) and can be expensive . If you don't have the skills available to do a GOOD job then a pu job with badly fitting boards will under perform dramatically .

If you can't be sure of very good workmanship .....use a certified breathing felt . use battens and counterbattens over the felt to give a 50 vent space over the felt . Oversize your rafters to 225mm and fill between them with high density quilt insulation . then run 50 pu boards below the rafters and foil tape the joints .

ircoha

sinnerboy wrote: »

50mm vent gap - in this case is a "belt and braces" approach . IF the OP is CERTAIN that an agrement certified breathable felt , such as you named , is used AND is certain that tiles are fixed on battens and counterbattens to give a 50mm vent space OVER that felt .... than 50mm vent space under would not be needed . I am guessing the OP will have difficulty establishing all this for certain and so am recommending the 50mm vent gap below the felt .

I am not sure what you asking me about internal walls - if you means internal faces of external walls - I will share my thoughts on the spec I advised the OP as follows

1. aiming to get max u value at optimum insulation thickness . PU's can't be beaten here .
2. OP states a desire for min 50 pu - I am suggesting 100 - but in two 50 layers because elecs usually make mess of deep insulation layers

So 50 wide x 25 deep battens are fixed to the blockwork . Important to run continuous battens horizontally at top ( ceiling ) level and bottom (skirting) level to help restrict air flow to the battens cavity . Battens cavity is where elecs should be - it is dangerous to allow them overheat by being sandwiched in insulation

First layer of pu next , foil faced both side is screw fixed to battens . Foil taping to board joints assists vapour control . If OP budget can't stretch any more - foil backed plasterboard is screw fixed through pu into battens now .
( Alternatively polythene vapour check and regular plaster board ) .

If the OP budget can take it and if internal room sizes are not too tight a second layer of pu , with board joints staggered relative to first layer , goes on next . Long screws through pu into battens . Instruct electrician to cut only this second layer for elec points - i.e first pu layer continues unbroken behind elec back boxes . Heating pipes ( unlike cables can happily be sandwiched between the pu layers , by cutting a chase in the second pu layer . ( OP has ufh so this does not arise ) . Again second pu layer is foiltaped at joints - to further enhance vapour resistance . Foilbacked plasterboard next ( fixed with long , drilled screw fixing into battens ) .

Composite plasterboards are often used , but I like the opportunity to tape the pu board joints by using pu separate to plasterboard .

When you ask how to seal off cavity around opes I take it you mean the battens cavity . Ensure that the battens , (required for board fixing any way ) run unbroken around the opes .

Lastly insulated jambs around openings . Frames are typically between 44 - 50mm wide and located 10mm proud of the opening . So block face to frame edge is approx 54-60mm . Here I would dab on the ( 25+12) composite board , which will leave 13-20 mm visible frame margin . I like to make the inner block opening 20mm larger than outer block opening to give a bigger margin ..

I hope understood and answered your queries

Thanks: all 100% except I was not clear on the cavity closers
http://www.subframes.co.uk/eurocell.htm shows what I meant by cavity closers.

The parent link http://www.subframes.co.uk
has a good selection of suppliers

sinnerboy

you mean the cavity of the block wall - not the batten cavity of the dry lining ....

well I prefer to use a cavity closer block and insulated DPC - like here

http://www.plysolene.com/Plyload3.html

davidoco

pbergin wrote: »

I think it is too easy to leave air gaps either side of the board.
:

Xtratherm do a product called Rafterloc which I used in my attic room in roof. It's precut 100 mm poliso with a tolerence for fitting between the rafters of between 10 and 30 mm.

No worries about big air gaps with it.

DLBuild

Would it be advisable to batten for drylining above sticking the boards directly to the wall? What are adv/disadv of these two methods?

marielle

"check that your roof membrane ( below tiles ) is breathable . i.e speak to product supplier of material . you may or may not need to ventilate BELOW the felt depending on this answer ."

membrane NOT breathable. So will be leaving 50 mm gap. Plenty of vents in soffit so should be enough for ventilation.

"then cut kinsgpan / xtratherm type boards betwween the rafters , to the max depth possible , still leaving a 50 space below the felt ".

We are using the 80mm foil backed kingspan in bewteen the rafters cut to size. saw one of these xtratherm boards that are kinda pre-cut to make it easy to fit between the rafters. are these really any better at getting a better fit? It was put up and kinda bent towards the tiles. Is that ok?Also, is it ok that the foil back is torn to bits since the board is precut? Shouldn't that be all one piece?

"then run min 50 thick kinsgpan / xtratherm below the rafters . foil tape the joints . foil tape to velux frames and any other pentartions - such as vent pipes then run foilbacked plasterboard over and skim . dont use recessed lighting"

My builders answer to that is just tape the boards to the rafters using foil tape, that will do for airtightness. Will it do?

"thirdly walls . batten out with timber 50 x 25 . run battens continous at skirting level and at ceiling level . cables and pipes go in 25 batten cavity . run 50 kinsgpan / xtratherm over . foil tape joints if internal space allows , run another 50 kinsgpan / xtratherm again and foil tape joints . foil tape to window frames ,door frames and around any other wall penetrations then run foilbacked plasterboard over and skim ."

I think my builder is thinking of just sticking the 50mm boards up and plastering on top. Will that be useless? Should I at least put some foiled back board on top of the 50mm kingspan?
Also, the chasing and first fix electrics are already done now so isn't it a bit late to be battoning since the wires and boxes are already in?

"the first floor is a big concern - UFH pipes must have insulation below - you will just be heating your pre cast floor slabs ................."

Not much I can do about that now though....what will it mean though. UFH runs downstairs and upstairs and heat rising, does that mean my downstairs rooms will be cold or anything? In that case, should I insulate the ceilings to keep heat downstairs?

sinnerboy

I advise rads not ufh to upper level so

Decide whose advice you trust more on this or other matters - your builders or posts here

marielle

bauderline wrote: »

Folks,

I have hired a BER Assessor to provide FULL insulation specifications for me backed up with the calculations that I can provide in black and white to my builder. Cost was 100 euro, I would say the best 100 euro I will ever spend !

He is also going to work with me during the course of construction to advise on the various options for heating, water, ventilation, air tightness with a view to attaining the best possible rating for the house on completion. That will cost around another 400 euro but will include the final cert.

If you are going to build your own house get a professional in to draw up a formal spec for insulation and your energy efficiency rating as this stuff is now way too important to leave to guesswork.....

Sorry for hijack... but worth saying....

baud.

Could you PM me too with these details please? I would love to see what he can do for me.... Thanks

marielle

sinnerboy wrote: »

I advise rads not ufh to upper level so

Decide whose advice you trust more on this or other matters - your builders or posts here

Well, I would like to know why I should invest in a totally new heating system upstairs on top of the one i already have! Are you saying that upstairs will not be warm because there is no insulation on the floor? So much so that i should add rads? This is no small expense so i guess you can understand my hesitance....

marielle

DLBuild wrote: »

Would it be advisable to batten for drylining above sticking the boards directly to the wall? What are adv/disadv of these two methods?

I would second this question..... if I'm going to be using a composite board with 38mm insulation and 12.5 plaster board, then what's wrong with screwing the board with plastic screws through it onto the wall then skim over that? Nevermind the fact that this might not be enough insulation to meet the regs for a minute. Surely these boards are designed to be used this way. They are foil backed so doesn't that work as a vapour check? I guess you can't tape the joints then but is that so much of a gap that it matters that much?
Should you leave a gap behind the board or can you stick them on directly? What about cutting the openings for sockets and such likes are you loosing much heat through there?

Villain

If there is no insulation under the UFH then a large amount of heat from the UFH will simply be obsurbed by the concrete and mesh under the UFH i.e. little heat will be dispersed around the house, now if you can get it air tight as possible and have a good HRV system then the amount of heat needed will be reduced but when a cold blast hits you will basically be heating the concrete floor.

Just my 2 cents

ircoha

marielle wrote: »

I would second this question..... if I'm going to be using a composite board with 38mm insulation and 12.5 plaster board, then what's wrong with screwing the board with plastic screws through it onto the wall then skim over that? Nevermind the fact that this might not be enough insulation to meet the regs for a minute. Surely these boards are designed to be used this way. They are foil backed so doesn't that work as a vapour check? I guess you can't tape the joints then but is that so much of a gap that it matters that much?
Should you leave a gap behind the board or can you stick them on directly? What about cutting the openings for sockets and such likes are you loosing much heat through there?

These issues has been discussed at length on a number of threads on this forum.

One suggestion is to search using the word mould in the Construction and Planning section

the attachment shows what the result looks like
Otherwise search for posts from people like Viking House.

If you wish, start with this one, which I opened and it got some very good input from people who know alot more about this stuff than I ever will.

http://www.boards.ie/vbulletin/showthread.php?t=2055162844&highlight=Mould

By sticking them directly on the wall you run the risk of mould growing behind the insulation on the inner face of the wall and potentially creating a sick building.

The battens create an air gap and also allow for pipes and cables to be run without having to 'rebate' the insulation.

If the battens do not provide an airtight gap then any insulation in the cavity is of no value.

The key point here, IMO, is that
as we increase our understanding of what is good and bad practice,
as more products come on the market and
we are faced with increased insulation and air-tightness standards,
what is 'best' current practice is a moving target to a certain degree.

However, if the building work is carried out to a poor standard by people who dont either care about or understand the issues then all the specs are meaningless.
This is why increased compliance with standards is included in the new part L
http://www.environ.ie/en/Publications/DevelopmentandHousing/BuildingStandards/FileDownLoad,16557,en.pdf

Hope this helps.

sinnerboy

I think I have written enough . good luck with your works

marielle

By the way...I looked on the SEI web site and looked some names up for my area but saw the name of an engineer I know who is a complete idiot who couldn't even use autocad properly when he did our plans so i'm thinking that this sounds like a total rip off of a scheme and any idiot can be an assessor. Again, how can I be sure I'm asking advice form someone who knows what the hell they are talking about??? Anybody know a good guy who can give me advice in the Galway area?

muffler

marielle wrote: »

By the way...I looked on the SEI web site and looked some names up for my area but saw the name of an engineer I know who is a complete idiot who couldn't even use autocad properly when he did our plans so i'm thinking that this sounds like a total rip off of a scheme and any idiot can be an assessor. Again, how can I be sure I'm asking advice form someone who knows what the hell they are talking about??? Anybody know a good guy who can give me advice in the Galway area?

No we cant give you advice because we are all idiots.

Figure it yourself and with an attitude like that you should be determined enough

marielle

muffler wrote: »

No we cant give you advice because we are all idiots.

Figure it yourself and with an attitude like that you should be determined enough

OMG I wasn't referring to anyone on this forum when i said 'someone who knows what the hell they are talking about'!!!! I have got better advice on my build from the people here than any professional i have been dealing with on my build so far

In fact i'll be straight up and say it, I recognised a name of an engineer i have dealt with on my build on the SEI website - and he really was terrible to deal with, i had to effectively fire him and hire a different engineer. He didnt even know the basics about the planning application process, he cost us a lot of time and several applications. Now having seen his name on the SEI website I am afraid if i randomly pick a name from the list there i might end up with someone else like him, so i am hoping someone in the Western region may have dealt with someone good from that site they may be able to recommend

sorry if i wasn't clear in my previous post, the last thing I would ever do to everyone who has helped me on this forum is give out or insult anyone

sinnerboy

I was inclined to write no further , but I recognise that your situation must be stressful .

I shall refrain from "tekky" talk now

Your building will lose heat via

1. the building fabric
2. ventilation ( intentional through openings ) and un-intentional ( degree of air tightness of the building )
3. the efficiency of your heating system

So

1. insulate to very very max you can . buy the best windows ( u value ) you can
2. HRV is an excellent way to go ONLY if you get a very air tight building . I will PM you a good contact . Use them . You should not be thinking of an open fire .
3. Insulate your water storage tank as best you can . Max insulation wrap and insulate the studwork of the cylinder enclosure ( hot press ) . Insulate well to primary pipework . Get best re assurance you can on the heat pump - check SEI website for model proposed . Adding solar panels may be good idea ( BER assessor to call this )

Make 3 appointments

BER assesor ( who is also a building professional - not estate agent type )
Air tightness company ( as per PM)
An architect to oversee the lot ( could also be BER chap )

Your builder will probably resent this intervention - but "manage" that . Best to select an experienced Architect to negotiate the spec changes and negotiate the cost implications . Builder will be entitle to charge more for spec changes.

You may be groaning at cost implications . We will all face higher and higher fuel bills in the near future . You will too no matter what you do . So get the building right so your increases are minimised .

On UFH in particular . You'r upper floor pipes are useless I am sorry to tell you Your floor will be warmed but you will not . Unless the ground floor insulation has been placed immediately below the UFH pipes - those pipes are useless too . Insulation has to located directly below the pipes - or it won't work .

Without getting the concrete breakers out you may instead look to use low temp rads . They are about 30-40% bigger than normal to distribute heat at lower temperatures that heat pump provides

So in all sincerity - good luck

marielle

sinnerboy wrote: »

I was inclined to write no further , but I recognise that your situation must be stressful .

I shall refrain from "tekky" talk now

Your building will lose heat via

1. the building fabric
2. ventilation ( intentional through openings ) and un-intentional ( degree of air tightness of the building )
3. the efficiency of your heating system

So

1. insulate to very very max you can . buy the best windows ( u value ) you can
2. HRV is an excellent way to go ONLY if you get a very air tight building . I will PM you a good contact . Use them . You should not be thinking of an open fire .
3. Insulate your water storage tank as best you can . Max insulation wrap and insulate the studwork of the cylinder enclosure ( hot press ) . Insulate well to primary pipework . Get best re assurance you can on the heat pump - check SEI website for model proposed . Adding solar panels may be good idea ( BER assessor to call this )

Make 3 appointments

BER assesor ( who is also a building professional - not estate agent type )
Air tightness company ( as per PM)
An architect to oversee the lot ( could also be BER chap )

Your builder will probably resent this intervention - but "manage" that . Best to select an experienced Architect to negotiate the spec changes and negotiate the cost implications . Builder will be entitle to charge more for spec changes.

You may be groaning at cost implications . We will all face higher and higher fuel bills in the near future . You will too no matter what you do . So get the building right so your increases are minimised .

On UFH in particular . You'r upper floor pipes are useless I am sorry to tell you Your floor will be warmed but you will not . Unless the ground floor insulation has been placed immediately below the UFH pipes - those pipes are useless too . Insulation has to located directly below the pipes - or it won't work .

Without getting the concrete breakers out you may instead look to use low temp rads . They are about 30-40% bigger than normal to distribute heat at lower temperatures that heat pump provides

So in all sincerity - good luck

Thanks again for your suggestions. They are much appreciated indeed.:D
I will definitely contact the guy you suggested.
Just in case this makes any difference re my UFH situation, the pipes downstairs are clipped onto a plastic mat with its own insulation which is also laid on top of some Kingspan insulation so we should be ok there. Also, note that most of the main living area downstairs is open plan with a double height space and gallery so a lot of the warm air will be travelling upstairs anyway through the void. Might that help my situation in any way, saving me from having to install rads? I really hate rads , hence the UFh choice in the first place.
Also note there are no vents anywhere in the house, we have no open fire, we are installing 3 solar panels for our hot water. The whole heating system : heat pump, tanks, boiler, solar panel expansion tank,.... are installed in the shed, about 3 meters from the house and the whole installation looks like a scifi set, silver bubble wrap insulation tied around every pipe in sight!! I'm really hoping that was done properly!!
The heat pump is 12kw and it is registered with SEI, so is the installer.
Just to share another pain in my neck, the builder is my father in law!!!! At least we are doing this via direct labour so I don't have a contract to worry about!!! It is harder to tell him where to go when the need arises though!! All I can say is : never again!!!!

sinnerboy

If you have enough head space and if it does not make a bags of your stairway (already installed or not ? ) - you could add a layer of 50 ks + 40 pfa "easiscreed" over . This adds 90mm to your floor - and takes same from head room . Might be a runner ?

marielle

sinnerboy wrote: »

If you have enough head space and if it does not make a bags of your stairway (already installed or not ? ) - you could add a layer of 50 ks + 40 pfa "easiscreed" over . This adds 90mm to your floor - and takes same from head room . Might be a runner ?

stairway not in yet so no issue there but where would you put the added insulation and easyscreed? Do you mean downstairs to add to what I already have?

sinnerboy

just upstairs . sounds like ground floor is ok

marielle

sinnerboy wrote: »

just upstairs . sounds like ground floor is ok

I'm probably being thick here but if you put insulation on top of UFH upstairs then another screed, aren't you preventing the heat from getting into the room at all? How would that help me? Unless you mean laying another layer of pipes above the layer of insulation?

sinnerboy

marielle wrote: »

Unless you mean laying another layer of pipes above the layer of insulation?

Yes this is what I mean

ardara1

Just throw'n my oar in here Sinner - If the temperature in the bedroom is 18 ish and below that 21 ish - is there not an argument that you don't really need insulation up there - the slab its self will be somewhere between these 2 temperatures.

Unless it's just to give more accurate control of the zones?

sinnerboy

How could the temp be 18 degrees up there ?

The first floor ufh will discharge all its heat energy into to the conc floor slab . An then into the supporting masonry structure . Unless the ufh is left on 24/7 the upper level will never heat up

ardara1

The typical temp in a bedroom (and for calc purposes in DEAP) is 18degrees - the occupants will get to this in some manner - even a dimplex heater. So if the temperature are similar - is there that much transfer up and down? The concrete floor will reach the UFH temp and radiate heat much like solar gain floor. - but perhaps up & down? Do know - just mulling ut over -
I'm not a great fan of underfloor heating anyway.

Mellor

Heat will always travel from hot to cold. If the slab was c.20 deg and the room was 18 deg. the pipes will be about 45 deg, so the delta temp is almost the same (25deg vrs 27deg), so alot of heat is going to pass into the slab, alot more than the room. Insulation here is a must.

ardara1

Mellor wrote: »

Heat will always travel from hot to cold. If the slab was c.20 deg and the room was 18 deg. the pipes will be about 45 deg, so the delta temp is almost the same (25deg vrs 27deg), so alot of heat is going to pass into the slab, alot more than the room. Insulation here is a must.

But the slab can't overheat surely? - will the slab not just 'radiate' that heat back into the room - or rooms?

sinnerboy

no . only if heat was on 24/7 . waste of energy . best thing is with UFH - keep fabric to be heated to min .

75mm screed with UFH takes about 1 hour for user to feel heat - if tiled - about 2 hours if timber floor / carpet . good thing about easi screed is 40mm reduces this time period .

UFH pipes direct onto conc floor slab - brrrrr !

DLBuild

Some great posts here folks.
Mind if I ask what the consensus is with regard to rads vs UFH on first floor. I'm pretty certain i'd like to have UFH downstairs and most flooring materials downstairs support this. However, upstairs where most of the day no heat is required would UFH be a bit of overkill? Would it be more economical to have rads coming on for an hour before bedtime upstairs?
The more i trawl through old threads the more confused i get with regard to all of these issues. I think Boards.ie should set up polls to gauge consensus on certain issues to help the poor old information seeker like myself.
Slainte.

Villain

Polls are easily abused by vested interests, ufh upstairs imo really only works when you have a concrete slab between floors and a lot of insulation directly under the piping, also a lot of people only use upstairs for bedrooms which are only used at night, so trying to keep heat upstairs while not having the heating on all the time can be a tough juggling task.

The main advantage imo is having heated floors when you step out of bed or especially when you go to the bathroom, however there are electric UFH mats which can be used for the bathroom, type of flooring cover is a bit more restricted too.

sinnerboy

DLBuild wrote: »

Some great posts here folks.
Mind if I ask what the consensus is with regard to rads vs UFH on first floor. I'm pretty certain i'd like to have UFH downstairs and most flooring materials downstairs support this. However, upstairs where most of the day no heat is required would UFH be a bit of overkill? Would it be more economical to have rads coming on for an hour before bedtime upstairs?
The more i trawl through old threads the more confused i get with regard to all of these issues. I think Boards.ie should set up polls to gauge consensus on certain issues to help the poor old information seeker like myself.
Slainte.

About 4 / 5 of our clients go for UFH ground floor - rads first floor . for a no of reasons

UFH is a slow response but this ok in the daytime spaces . Families with small kids and varying bedtimes like the flexibility / responsiveness of rads - esp with TRV's . If cold night , turn first floor stat up and 20 mins later - all nice and warm up there . If too hot - vice versa .

UFH means furniture layout is "free-er" without rads . Less of a big deal with bedrooms .

marielle

Can I ask about a product that I actually had thought of using upstairs to start with but then decided to go with a screed instead.:mad: It is called Heatrack : http://snipurl.com/1zvnj and basically the pipes are stuck onto a board with already has grooves in it. No need for screed, you just stick your wood floor finish on top. Quick to install as well... could that be the answer to my problems?

sinnerboy

marielle wrote: »

Can I ask about a product that I actually had thought of using upstairs to start with but then decided to go with a screed instead.:mad: It is called Heatrack : http://snipurl.com/1zvnj and basically the pipes are stuck onto a board with already has grooves in it. No need for screed, you just stick your wood floor finish on top. Quick to install as well... could that be the answer to my problems?

you needed a screed any way to knit the ( presumably precast conc ? ) floor slabs together . placing the UFH pipes in there was the boo boo

this is an alternative to the product you posted

http://www.tem.ie/heat_dist_under.htm

a product like these will eliminate the screed and speed up the response time ( the time lag between heat on and you feeling the heat ) .

But you still need the insulation layer , so you don't waste energy heating the fabric of your floor structure .

ardara1

Villain wrote: »

Polls are easily abused by vested interests, ufh upstairs imo really only works when you have a concrete slab between floors and a lot of insulation directly under the piping, also a lot of people only use upstairs for bedrooms which are only used at night, so trying to keep heat upstairs while not having the heating on all the time can be a tough juggling task.

The main advantage imo is having heated floors when you step out of bed or especially when you go to the bathroom, however there are electric UFH mats which can be used for the bathroom, type of flooring cover is a bit more restricted too.

Would slippers not be cheaper?

marielle

sinnerboy wrote: »

you needed a screed any way to knit the ( presumably precast conc ? ) floor slabs together . placing the UFH pipes in there was the boo boo

this is an alternative to the product you posted

http://www.tem.ie/heat_dist_under.htm

a product like these will eliminate the screed and speed up the response time ( the time lag between heat on and you feeling the heat ) .

But you still need the insulation layer , so you don't waste energy heating the fabric of your floor structure .

Fair enough i still would need insulation underneath it but at least i would be loosing less than 90mm overall though! Also the system would be way more responsive than a normal screed system. Can I mention the dreaded word "foil" to use as an insulation under this or will you shoot me?:p

sinnerboy

marielle wrote: »

Can I mention the dreaded word "foil" to use as an insulation under this or will you shoot me?:p

no . I might send you an electric blanket and some cocoa

Mellor

marielle wrote: »

Can I mention the dreaded word "foil" to use as an insulation under this or will you shoot me?:p

This would be the worse application of foil insulation, which is already a badly performing insulation.

sinnerboy wrote: »

you needed a screed any way to knit the ( presumably precast conc ? ) floor slabs together .

I think the product posted was designed to be used over timber floors eliminating the need for a screed.

When there is insulation between the screed and precast slab, does the screed haves any structural benefit. I wouldn't of thought so

galwaytt

Mellor wrote: »

I think the product posted was designed to be used over timber floors eliminating the need for a screed.

We have done a pair of semi's with it, and it seems to work very well.

marielle

galwaytt wrote: »

We have done a pair of semi's with it, and it seems to work very well.

Can I ask what you used under them? Did you go for the 50mm KS or did it come with its own insualtion?

sinnerboy

Mellor wrote: »

I think the product posted was designed to be used over timber floors eliminating the need for a screed.

It can also be used in OP situtaion

Mellor wrote: »

When there is insulation between the screed and precast slab, does the screed haves any structural benefit. I wouldn't of thought so

wouldn't do this anyway . ufh in upper level pc floor is

UFH pipes in screed ( or special boards )
insulation
structural screed
pc slabs