Floor insulation

john_cappa

What options do I have for floor insulation?

My provisional spec recommends kingspan TF70 120mm. I understand this is pricey stuff.

Are there alternatives that offer the same performance? (I think the kingspan is u value of 0.022 w/mk)

sydthebeat

Xtratherm thin-r XT-UF is an equivalent product

any other polystyrene based product will need to be deeper to achieve the same performance

North West

Hi
Try Ballytherm for a price
NW

john_cappa

sydthebeat wrote: »

Xtratherm thin-r XT-UF is an equivalent product

Thanks. That's looks like a decent alternative. I take it I would need the same thickness of the above insulation to achieve the same performance as the kingspan (120mm)??

sydthebeat wrote: »

any other polystyrene based product will need to be deeper to achieve the same performance

I don't think this is an option sadly.

john_cappa

North West wrote: »

Hi
Try Ballytherm for a price
NW

http://www.ballytherm.ie/floor-insulation/

I take it table 4 is the one I would be concerned with? The u value for ROI in the table of 0.21, is that the same as the kingspan product I mentioned? Just using different units?

sydthebeat

john_cappa wrote: »

(I think the kingspan is u value of 0.022 w/mk)

this is where you are getting confused

0.022 w/mk isnt the u value, its the thermal conductivity value

the conductivity stays basically the same as the thickness increases, but the u value of an element of construction lowers (gets better!) as the thickness of the insulation increases.

john_cappa

sydthebeat wrote: »

this is where you are getting confused

0.022 w/mk isnt the u value, its the thermal conductivity value

the conductivity stays basically the same as the thickness increases, but the u value of an element of construction lowers (gets better!) as the thickness of the insulation increases.

That's makes very obvious sense lol.

How would I calculate what thickness of the ballytherm product I would need to achieve the same performance?

Edit: also see my question above re the xtra therm product u mentioned syd. Cheers.

sydthebeat

the xtratherm product is the equivalent... it has the same thermal conductivity, so it equates in thicknesses.


you can see from table 3 here that the ballytherm product has the same TC value as well.


they are all pretty much the same product.

they are all polyisocyanurate

john_cappa

sydthebeat wrote: »

the xtratherm product is the equivalent... it has the same thermal conductivity, so it equates in thicknesses.


you can see from table 3 here that the ballytherm product has the same TC value as well.


they are all pretty much the same product.

they are all polyisocyanurate

Perfect got it. On phone so its pretty hard to read spec sheets but will have a good look tomorrow.

Some options at least to see if some cash can be saved.

hexosan

What thickness of eps would be needed to achieve the same value as the Kingspan or Xtratherm.

sydthebeat

hexosan wrote: »

What thickness of eps would be needed to achieve the same value as the Kingspan or Xtratherm.

EPS = expanded polystyrene

This can have a variable thermal conductivity usually in the range of 0.037 - 0.033 so it really does depend on exactly the product thats selected.

for example 60mm xtratherm polyiso XT/CW ODP equates to 100mm warm-r EPS 50

in general, id suggest that approx 50% more needs to be added in depth

john_cappa

Expensive stuff the tf70/xtra. Cheapest I can get so far is 28+vat per sheet. Need 44 sheets. That is for the 100mm. 120 is alot more expensive (why I don't know given that it should be pro rata 20% extra but its more like 35% dearer).

Waiting in ballytherrm to ring back. They would need to be a lot cheaper to stray really though.

john_cappa

Performance difference is fairly small between 100 and 120mm. Hmmmm is it worth the extra 600-700 quid?

fclauson

What is your total depth - 150 or 200 is better

john_cappa

What do you mean total depth?

BryanF

fclauson wrote: »

What is your total depth - 150 or 200 is better

john_cappa wrote: »

What options do I have for floor insulation?

My provisional spec recommends kingspan TF70 120mm. I understand this is pricey stuff.

Are there alternatives that offer the same performance? (I think the kingspan is u value of 0.022 w/mk)

with 120mm thickness = approx 0.18 u-value

John if your going with UFH this wont comply BUT regardless you should take FClausons advice on this one

note that a BER is really required to valuate the u-value requirements

john_cappa

BryanF wrote: »

with 120mm thickness = approx 0.18 u-value

John if your going with UFH this wont comply BUT regardless you should take FClausons advice on this one

note that a BER is really required to valuate the u-value requirements

I am not installing UFH. I had an a proviso BER done and they specified 120mm of kingspan or equilivant.

fclauson

So - the more the merrier :cool:

200 works really well - do the heat loss maths

john_cappa

Will stick with the 120 mm so! Can't afford 200!

Carbonnet

Thickness 0.100
Divide by Conductivity (PIR) 0.022

= Resistance 4.55


Once you have the Resistance you can get the thickness of Alternative (Alt) materials

4.55 x Conductivity of Alt (Say EPS HD) 0.032 = 0.146 (m) =

146mm HD EPS is same thermal value of 100mm PIR

But not compressive strength etc -

pharmerboy

Ive been pricing around for 100mm floor insulation sheets. Cheapest Ive found is £26.50 (31 euro) + vat a sheet. Anyone better this? I need about 100 sheets of the stuff so every little helps!