Floor insulation

creedp

I’m planning to install 200mm of EPS silver insulation under a 100mm screed on the ground floor. I’m installing UFH. I’ve spoken to a number of companies who have advised that the Std Density option is appropriate for a domestic setting. However, one company advised that as I was going with UFH I should really install High Density option. My builder/engineer don’t have problem with SD insulation option but are inclined to listen to the guy recommending HD option. I know the HD option has a slightly higher U value but the price differential is very substantial.

Anyone any views on whether it would be worthwhile going with HD EPS silver in my circumstances?

Thanks

Carlow52

I know next to nothing or less about UFH but the math here seems, at least in theory, pretty standard.

You have a 100mm slab sitting on 200mm of insulation which is sitting on concrete sub-floor

The slab will be at say 18 degrees C and the sub floor at say 10

Therefore the heat loss through the 200mm of insulation can be calculated for both types and the heat saved can be valued to see what the break-even/payback period is.. The saving when oil at 300 a barrel will be twice that when it is at 150:)


I would go with higher spec and ensure its done right:)

creedp

Carlow52 wrote: »

I know next to nothing or less about UFH but the math here seems, at least in theory, pretty standard.

You have a 100mm slab sitting on 200mm of insulation which is sitting on concrete sub-floor

The slab will be at say 18 degrees C and the sub floor at say 10

Therefore the heat loss through the 200mm of insulation can be calculated for both types and the heat saved can be valued to see what the break-even/payback period is.. The saving when oil at 300 a barrel will be twice that when it is at 150:)


I would go with higher spec and ensure its done right:)

Thanks Carlow52 and I agree with you that all thinks being equal always go gor higher spec. Unfortunately everyone has restrictions to operate within. I was originally speccing to go with 150mm PIR but having considered issue re off-gassing etc felt that EPS would be a better alternative. It works out that 200mm SD silver EPS has approx same U value as 150mm PIR so that why I opted to go with SD originally. Yes the HD EPS has a slightly better U Value, i.e. 0.12 -v- 0.11 but, for my floor, cost €1,092 (55%) more. As I said we all like to install the best option but at what price? The marginal increase in U value would seem to be dwarfed by the substantial increase in price. In any case, if it was purely u value I was after I would be better off installing 200mm of PIR which would give me a substantially better result that the 200 EPS HD. Where could it all end?

Carlow52

The gassing off issue also drops the long-term performance of PIR so you need to be sure u are comparing like with like.

Some PIR is now quoted for the lower U value but you need to be sure.

Must say am surprised by the cost/ performance numbers

sydthebeat

I would think the UFH manufacturers reluctance to install on 200mm EPS is probably more down to the structural element of the insulation. I would imagine 200 EPS as being quite "bouncy". Is the 100mm screed structural, is it reinforced?

creedp

sydthebeat wrote: »

I would think the UFH manufacturers reluctance to install on 200mm EPS is probably more down to the structural element of the insulation. I would imagine 200 EPS as being quite "bouncy". Is the 100mm screed structural, is it reinforced?

Excuse my ignorance but when you say structural .... I have a 150mm reinforced sub floor and the insulation is laid on this followed by a reinforced 100mm screed. I was going with 80mm screed with 20mm tiles but because my wife wanted a polished concrete finish I just increased screed to 100mm.

In fairness its the insulation supplier who has benn suggesting going with HD insulation for UFH. However, I'll get onto the UFH guy to confirm which he considers more suitable.

Thanks

creedp

creedp wrote: »

Excuse my ignorance but when you say structural .... I have a 150mm reinforced sub floor and the insulation is laid on this followed by a reinforced 100mm screed. I was going with 80mm screed with 20mm tiles but because my wife wanted a polished concrete finish I just increased screed to 100mm.

In fairness its the insulation supplier who has benn suggesting going with HD insulation for UFH. However, I'll get onto the UFH guy to confirm which he considers more suitable.

Thanks

Just to add here that I've spoken to UFH guy and he now tells me that neither SD or HD EPS have enough mechanical strength to hold underfloor pipes which would move once screed is being poured causing a lot of hassle. He said the top layer of insulation should be xtratherm or equivalent to hold the UFH pipes and I could put what I liked underneath.

Anyone any comments on this? Has anyone fitted UFH pipes along with EPS insulation and what was your experience. If I do have to go with xtratherm on top what is the minimum thickness I could use?

Thanks for help

Carlow52

How are the pipes fixed?

I would have thought it the proper proprietary systems are used then its not a problem bu if its the irish solution of a few briars cut and pushed into the EPS then...

creedp

Carlow52 wrote: »

How are the pipes fixed?

I would have thought it the proper proprietary systems are used then its not a problem bu if its the irish solution of a few briars cut and pushed into the EPS then...

Ah Carlow52 you know a bit more about UFH than what you were letting on earlier!! To be honest I don't know how the pipes are fixed. This building lark is wearing me down is all I can say. Ill ask the guy how he is proposing to fix pipes but given his concern with EPS I suspect you're right about the briars! When you say its the Irish way do you mean its the common approach or that its yesterday's/the cowboy way? Are the proprietary systems much more expensive?

Carlow52

Nothing like exposing a closet UFH geek:D

I found the attached image when I googled images for UFH

I have only rarely seen it used here.
Yes it will cost but...

The other issue if the screed is dropped form a height then the lateral pressure will move most things

creedp

Carlow52 wrote: »

Nothing like exposing a closet UFH geek:D

I found the attached image when I googled images for UFH

I have only rarely seen it used here.
Yes it will cost but...

The other issue if the screed is dropped form a height then the lateral pressure will move most things

No point staying in the closet, especially in this weather:)

Looked at the link you kindly posted and I have to say that's exactly how I imagined it would be done based mainly on looking at other UFH related websites/links. THe guy I'm ended up getting to install the UFH (not the builder) charged significantly more that the builder was seeking for this job, however, not sure if this princly sum covers the more expensive pipe fixing method. Will have to check.

Point taken also about dropping screed from a height. I wonder how many UFH pipes actually end up where they were originally located? Not great from an efficienty perspective. At least a radiator will be in the selected location.

Carlow52

I would be seeking a breakout of the pricing: x 100m of XYZ pipe at ABC a meter and so. The key is getting the make and not getting a no name.
As it happens I was passing a site today where the UFH pipe was being delivered so I asked for a piece

see here http://www.rbm.eu/kilma/it/indice_generale.html

for the fixing system

and here for the pipe
http://www.rbm.eu/en/en/cap14_00.html

this is what was on the pipe
RBM TITA-FIX PE-Xb/AL/PE o 16x2.0 –UNI 10954

Its not all in english but the pics are up to scratch

creedp

Carlow52 wrote: »

I would be seeking a breakout of the pricing: x 100m of XYZ pipe at ABC a meter and so. The key is getting the make and not getting a no name.
As it happens I was passing a site today where the UFH pipe was being delivered so I asked for a piece

see here http://www.rbm.eu/kilma/it/indice_generale.html

for the fixing system

and here for the pipe
http://www.rbm.eu/en/en/cap14_00.html

this is what was on the pipe
RBM TITA-FIX PE-Xb/AL/PE o 16x2.0 –UNI 10954

Its not all in english but the pics are up to scratch

Thanks Carlow52 for above. I had a quick look through and was blown away by the wide range of products. Didn't realise that the piping choice could be so complex. I had a look at the specification in my quote and the spec for the piping is 1675m of 18mm DOUBLEPLEX PE - Xb Oxegen Barrier Piping and 265m Underfloor quick Track & Pipe Staples. This is for a 2,800 sq ft house with UFH on both levels. Not sure how that compares to specifications in the above links.

The UFH contractor continues to advise that unless 50mm of Kingspan or equivalent rigid board is used under UFH pipes, the screed guys will have great difficulty keeping pipes in place. Also as I will have polished concrete finish on ground floor the 'screed' will have to be a 30N concrete mix and not regular sand and cenent screed, it is likely that this will cause even more problems for pipes so Im angling to have 150mm eps plus 50mm PIR on ground floor and simply going with 50mm PIR on 1st floor.

Carlow52

creedp wrote: »

Thanks Carlow52 for above. I had a quick look through and was blown away by the wide range of products. Didn't realise that the piping choice could be so complex. I had a look at the specification in my quote and the spec for the piping is 1675m of 18mm DOUBLEPLEX PE - Xb Oxegen Barrier Piping and 265m Underfloor quick Track & Pipe Staples. This is for a 2,800 sq ft house with UFH on both levels. Not sure how that compares to specifications in the above links.

The UFH contractor continues to advise that unless 50mm of Kingspan or equivalent rigid board is used under UFH pipes, the screed guys will have great difficulty keeping pipes in place. Also as I will have polished concrete finish on ground floor the 'screed' will have to be a 30N concrete mix and not regular sand and cenent screed, it is likely that this will cause even more problems for pipes so Im angling to have 150mm eps plus 50mm PIR on ground floor and simply going with 50mm PIR on 1st floor.

Just googled ur fixing spec and got this
http://hsb.ie/catagories.php?cat=11

so it seems that the track is glued onto the insulation at unspecified centres and the staples are then used to pin the pipe to the insulation.

I'm only guessing here

This is a world away from having the pipe completely surrounded by the screed.

For some doodling on the track.
2800 sq feet over 2 floors so 1400 per floor

say 46 by 30

265m is 875 feet/2 = 437 per floor/46= 10 rows over 30 feet => 1 every 3 feet.

Could be all wrong here but I am just doodling:)

ps I offered the other links yesterday to just show whats out there and the importance of knowing before they arrive on site with a tractor load of briars and some recycled qualplex:)

creedp

Carlow52 wrote: »

Just googled ur fixing spec and got this
http://hsb.ie/catagories.php?cat=11

so it seems that the track is glued onto the insulation at unspecified centres and the staples are then used to pin the pipe to the insulation.

I'm only guessing here

This is a world away from having the pipe completely surrounded by the screed.

For some doodling on the track.
2800 sq feet over 2 floors so 1400 per floor

say 46 by 30

265m is 875 feet/2 = 437 per floor/46= 10 rows over 30 feet => 1 every 3 feet.

Could be all wrong here but I am just doodling:)

ps I offered the other links yesterday to just show whats out there and the importance of knowing before they arrive on site with a tractor load of briars and some recycled qualplex:)

When I see the gear on the weblink I certaintly recognise the tracks, the pipe 'unwinder' and the staple gun. Am I safe to assume therefore that the specification I have been quoted for is acceptable? I'm interested in your doodling as I understand that UFH pipes should be closer with heat pumps due to the fact that HP work more efficiently at lower temps. Again apologising for not being technically adept [and moreso for being too lazy to work this out myself!] but is the '1 in very 3 feet' result above good or bad for my purposes?

Thanks again

Carlow52

creedp wrote: »

When I see the gear on the weblink I certainly recognise the tracks, the pipe 'unwinder' and the staple gun. Am I safe to assume therefore that the specification I have been quoted for is acceptable? I'm interested in your doodling as I understand that UFH pipes should be closer with heat pumps due to the fact that HP work more efficiently at lower temps. Again apologising for not being technically adept [and more so for being too lazy to work this out myself!] but is the '1 in every 3 feet' result above good or bad for my purposes?

Thanks again

I have NO idea what is acceptable or not here.

The tracks will run at right angles to the pipes so the spacing between pipe runs can be specified, subject to the minimum bend radius so u may have loops within loops.

As to whether a track every 3 feet is good enough I don't know but what I do know is that if 'Paddy installer' can get away with using less track and less staples then he will do it. The screed will hide a multitude

'Paddy installer' may only see a need for the track so as to get a smooth bend on each loop at each end: what happens in between could just be staples..

Again I ask the question: is stapling to the insulation up to scratch versus embedded in the screed with screed above and below.

creedp

Again I ask the question: is stapling to the insulation up to scratch versus embedded in the screed with screed above and below.

I'll ask my contractor on this, the spacing for the pipes and whether the track is used only for a smooth bend on each loop at end andreport back.

Would be very interested in views of others on these issues