What type of insulation for External wall ?

Bigbird1

Hi

Just wondering what brand of insulation people would recommend for the external wall. Looking at Xtratherm, kingspan and Ballytherm. It must be 110ml and have a thermal Conductivity of 0.021 W/m.k.

Ballytherm is the cheapest but not sure about it.

Thanks

BryanF

Sounds like you will also be drylining? Would you consider keeping all insulation in the cavity?

Bigbird1

BryanF wrote: »

Sounds like you will also be drylining? Would you consider keeping all insulation in the cavity?

All the insulation is in the cavity??

sydthebeat

Xtratherm partial fill starts at 0.022

Bigbird1

sydthebeat wrote: »

Xtratherm partial fill starts at 0.022

Would 0.022 be sufficient? Is it the U value or the thermal Conductivity figure that's important or both ?

Lumen

Bigbird1 wrote: »

Would 0.022 be sufficient? Is it the U value or the thermal Conductivity figure that's important or both ?

Thermal conductivity is independent of thickness so will tell you how insulating the material is, but you need to calculate or look up the U value for a given thickness to determine if your wall performance target will be met.

sydthebeat

Bigbird1 wrote: »

Would 0.022 be sufficient? Is it the U value or the thermal Conductivity figure that's important or both ?

You use the TC value to calculate the U value.

The higher the TC value, the more thickness you need to reach the same U value.

Bigbird1

sydthebeat wrote: »

You use the TC value to calculate the U value.

The higher the TC value, the more thickness you need to reach the same U value.

Ok thanks. So the spec I have on the BER is Xtratherm, 110ml, TC of 0.021. So on pricing other insulation manufacturers, they have the same size board, a lesser U value, but with a TC of 0.022. Would it be sufficient to go with this ?

sydthebeat

Bigbird1 wrote: »

Ok thanks. So the spec I have on the BER is Xtratherm, 110ml, TC of 0.021. So on pricing other insulation manufacturers, they have the same size board, a lesser U value, but with a TC of 0.022. Would it be sufficient to go with this ?

Theres very little difference between those to be honest... But you still need to check if you are meeting the levels you need to be regulation compliant

For example quilted insulation would typically have a TC value of 0.04.... Which practically means that you need about 50% more thickness to meet the same U value.

BryanF

I’m surprised it’s 110mm PIR for your walls, what size house is it

Bigbird1

BryanF wrote: »

I’m surprised it’s 110mm PIR for your walls, what size house is it

Its 2300 sq foot. 150ml cavity.

Bigbird1

sydthebeat wrote: »

Theres very little difference between those to be honest... But you still need to check if you are meeting the levels you need to be regulation compliant

For example quilted insulation would typically have a TC value of 0.04.... Which practically means that you need about 50% more thickness to meet the same U value.

Any quick way of checking if I'm compliant. Does the guy that did up the BER have to calculate this again ?

Bonzo Delaney

Bigbird1 wrote: »

Its 2300 sq foot. 150ml cavity.

Why isn't 150mm full fill cavity insulation speced

sydthebeat

Bonzo Delaney wrote: »

Why isn't 150mm full fill cavity insulation speced

Not required to meet minimum regulation