Should we go with kingspan or it pumped?

[CalvinHobbes]

Just wondering

Our plans say this " Ground Floor Construction
Provide Cemfloor liquid screed, depth to ensure a minimum of 25mm cover to underfloorheating pipes - to be confirmed with manufacturer (Laid in Strict Accordance to Manufacturers Specification) on 500 guage vapour barrier (all joints taped & sealed) laid over 150mm depth of PIR Kingspan, floorboard insulation made up in 2 layers with bottom layer 50mm depth & top layer 100mm depth on 150mm deep concrete floor slab with Radon Shield (DPM) Membrane under slab laid over 50mm sand blinding on min 300mm & maximum of 600mm depth of consolidated hardcore base....

 

Or a screed company offered this.....

 

For energystore TLA insulation 

160m2 @ 150mm

 

£3480

 

Estimated U Value 0.18 

 

For 160m2 of cemfloor liquid screed @ 50mm

 

£2700

 

I see on this many people discussing using Kingspan, price wise is there much difference? There doesn't seem to be. Everything is so bleeding expensive. 

[dpmiller]

what is the actual thermal quality of the TLA and does it need to be topped with a screed anyway?

[Conor]

TLA has twice the thermal conductivity of PIR. Much better off with 150mm PIR. Price comes in about the same once you account for labour for the PIR.  Still need 50mm liquid screed for both. 

[Jenki]

6 hours ago, CalvinHobbes said:

Estimated U Value 0.18 

This would not pass Scottish requirements. Is this correct? 

I prefer to put the UFH into a big concrete slab, so would go for maximum insulation PIR or EPS, we used 300mm of EPS, nit 150PIR would be equivalent, and UFH in concrete slab. Then allow for a thin layer of latex self leveling. It will be cheaper than concrete and screed and IMHO gives better results. 

"People" use liquid screeds for speed of heat up, your building an insulated / Airtight house(I hope), so slow and steady will win the race.

[SteamyTea]

6 hours ago, CalvinHobbes said:

Estimated U Value 0.18 

Right.  Not very good for UFH.

 

Take the example where the ground temperature is 10°C (quite high) and a mean flow temperature of 35°C.

 

0.18 [W.m^-2.K^-1] x 1 [m²] x 25 [ΔT] = 4.5 W.m^-2 of energy needed before you start heating the air in the room.

 

So if your room needs 10W.m^-2 you actually need to supply 14.5W.m^-2.

If you get the U-Value down to 0.1 W.m^-2.K^-1, you will only need to supply 12.5W.m^-2, a 15% saving.

[JohnMo]

6 hours ago, CalvinHobbes said:

Estimated U Value 0.18

Little confused, you have said you are doing a passivhaus, there is nothing passivhaus about 0.18.

 

You need 2.5x the depth with insulated concrete compared to PIR. Kingspan is just a brand name, plenty of competition in the marketplace. I bought online, it came direct from factory.

 

I would limit my choice to either

300mm EPS, slip membrane, UFH pipes, the screed or concrete, circa 100mm will allow you use as as storage heater, thin more like a radiator.

 

Or

200mm PIR in 2x 100mm staggered layers. Then as above.

 

If you are doing UFH aim for 0.1 U value

 

 

[CalvinHobbes]

Thank you!!!!! Right PIR it is. The architect specified 150mm (50 + 100)of Kingspan K103 so I just need to find out what is the equivalent from competitors. You say it should be 200 but that may be difficult at this stage in terms of do we have a spare 50mm?

[SteamyTea]

6 minutes ago, CalvinHobbes said:

I just need to find out what is the equivalent from competitors

You need to calculate the thermal losses, then find out the most effective method.

 

Getting the floor right is probably the most important thermal engineering thing you have to do, not as if you can change it once a few tonnes of building are on it.

 

 

[Jenki]

2 hours ago, CalvinHobbes said:

Kingspan K103

Some of these specific products are hideously expensive. Just use PIR, the slight difference on thermal performance can easily be taken care of with 10mm or 25mm more insulation.

I achieved 0.094 with 300mm EPS and concrete. Simple and cheap.

[CalvinHobbes]

OMG I finally twigged what is happening here thanks to you lot! All these near passive houses instead of putting the PIR down as directed people are putting down TLA. So everything else is undermined. Then when people complain how much the ashp is costing in electric they blame the ashp.

On top of that people there are insufficient people here trained to install or service them. Solar panel and battery R&D is moving at a fierce pace so putting in either now feel crazy. (PV news new cell up to 144%)

So here I am still getting told to put in an condenser burner and use TLA and put up old hat solar panels to compensate the SAP by 40%. Jesus, Mary, St Joseph and the wee donkey.

Well for fecking starters there is no way TLA is goiing down. None. Nada.  Oh yeah I was told too that PIR was sit because it was hard to cover all the pipes and sometimes it dropped. Is that because the builders suppliers told me builders that are using it for the floor are using ordinary PIR not the floor stuff with the better compression figures?

Side query,how likely is it there will be a leak in the UFH? Are radiators not safer?

Chill woman dear.

 

[Declan52]

Generally most of your services on the slab will be no more than a 50mm duct. You then use 50mm PIR floor insulation to cover the floor with tracks cut out where ever the ducts are going. A weak mix of sand and cement fills the gaps of the ducts and where you have cut the insulation and then whatever you have left goes on top, 100,150,200mm of PIR floor insulation. 

Unless your parking tanks on your living room floor then there is no chance PIR floor insulation will sink. 

I have 150mm of PIR then a membrane then my ufh pipes and 75mm of sand cement screed. Takes around 90 mins to you feel heat but once you turn your heating off  it will take hours to cool down. 

 

[CalvinHobbes]

• Thanks Declan, I have been watching you tube to understand this better. So you put the membrane down to stop it going in between any gaps (although it should be taped) and effectively tank it. So then the ufh goes down. One question, the fixings or staples? to hold the pipes in place - surely they piecer the membrane? Also architect told us "Provide Cemfloor liquid screed, depth to ensure a minimum of 25mm cover to underfloorheating pipes - to be confirmed with manufacturer (Laid in Strict Accordance to Manufacturers Specification) on 500 guage vapour barrier (all joints taped & sealed) laid over 150mm depth of PIR Kingspan, floorboard insulation made up in 2 layers with bottom layer 50mm depth & top layer 100mm depth on 150mm deep concrete floor slab" so only 25mm allowed for pipes? I doesn't sound much. Thats the height we have to play with. Also spark saying he would like to wire sockets from floor since ceilings high (less chasing etc)
•  

Edited April 17 by CalvinHobbes

[Declan52]

It's only tiny staples so no massive hole for the screed to follow into. Before your floor gets poured they should check each room and if needed a bit of tape will cover many sins.

Never seen the ground floor of a house wired from the floor. Your just making more work for yourself when the insulation needs to go down. How high are your ceilings??

25mm coverage on ufh pipes is standard. Pipe is probably 16mm then your 25mm so 41mm depth. How thick is your screed.

[Kelvin]

On 04/04/2024 at 09:59, CalvinHobbes said:

Thank you!!!!! Right PIR it is. The architect specified 150mm (50 + 100)of Kingspan K103 so I just need to find out what is the equivalent from competitors. You say it should be 200 but that may be difficult at this stage in terms of do we have a spare 50mm?

The K103 stuff (phenolic) is really expensive. Just use PIR at a minimum thickness of 150mm ideally more and all the PIR stuff is the same so buy on price. 

[CalvinHobbes]

Thanks Declan, but would the compression thing ok? Height is 2585 (see below). I got a price for Kingspan ThermaBoard TF70 / TP10 2400 X 1200 X 75mm Sheet - 1.00 30.32 Each 30.32 ZICSFB010 Kingspan ThermaBoard TF70 / TP10 2400 X 1200 X 150mm Sheet - 1.00 55.18 Each 55.18

Edited April 17 by CalvinHobbes

[CalvinHobbes]

Sigh, I think most people hearts are in the right place it's just we all tend to do what is tried and tested, wwhat we know. The MVHR guy told me today he met a 71 year old woman who is planning a house with no heating because she was assured it would work. He said he sees her wearing a warm coat when it's twenty degrees and thinks it will be a disaster.

[saveasteading]

On 04/04/2024 at 06:01, Conor said:

TLA has twice the thermal conductivity of PIR.

 

Their web page says it achieves 0.18 for Perimeter /Area = 0.4.

Intuitively that seems  very unlikely as it is eps (half as good as PIR) with cement binder (much worse). 

[Declan52]

1 hour ago, CalvinHobbes said:

Thanks Declan, but would the compression thing ok? Height is 2585 (see below). I got a price for Kingspan ThermaBoard TF70 / TP10 2400 X 1200 X 75mm Sheet - 1.00 30.32 Each 30.32 ZICSFB010 Kingspan ThermaBoard TF70 / TP10 2400 X 1200 X 150mm Sheet - 1.00 55.18 Each 55.18

 

Floor insulation is tested to industry standards to get it's compliance certificates so if it says it's ok for floors it's ok. Your buying it from a reputable builders yard not some guy at Nutts Corner market. You don't put cavity wall insulation under a floor for his reason.

Standard height would be 2400 so your not exactly adding massively to it. Mine are 2500 and it just gives a much nicer feeling of space. They won't be using a hammer and chisel to do the tracking so will take a few seconds extra to run the saw the trackers use. Keep the wires in the wall where possible. 

You don't have to use kingspan. It's just a brand. I have a house with not one kingspan board, it's all celotex. 

How much height have you from the top of your sub floor to your finished floor??

[CalvinHobbes]

Fair! 

[Mattg4321]

Tell the sparks he’ll be running his cables from above. Ridiculous idea to put them in the screed when not absolutely necessary 

[Mikey]

On 04/04/2024 at 01:45, CalvinHobbes said:

For 160m2 of cemfloor liquid screed @ 50mm

 

£2700

Where in the country are you being quoted this price?! I’ve just been quoted £5K for 165m2 cemfloor at 50mm depth 🤯