Help with U value calculation

[lakelandfolk]

Hello, We want to improve the insulation of our Church Hall which has 9" solid brick walls. Does anyone know how to calculate the U value if we fixed 100mm of PIR external wall insulation and render?                The internal plaster work is in poor condition so might also be worth considering fixing new plaster boards and skim,  the boards to include 30mm of PIR. Interested to know the U value of the EWI and also what value the insulated internal boarding would achieve. A ball park figure would suffice at this stage.

[SteamyTea]

Yes, I do.

 

 

 

[ETC]

If your church is old please get proper professional advice before you apply any type of insulation - internal or external. The external wall - depending on it’s construction may have been designed to “breathe” and adding insulation ad-hoc may cause more problems.

 

Having said that if you want to see what U-Value you can achieve with certain insulation types there are many online U-Value calculators that will give you what you need.

[ETC]

https://historicengland.org.uk/images-books/publications/eehb-insulating-solid-walls/heag081-solid-walls/

[IanR]

2 hours ago, lakelandfolk said:

Does anyone know how to calculate the U value if we fixed 100mm of PIR external wall insulation and render?   

 

100mm PIR would bring the 9" solid brick wall down to 0.25 U Value from around 1.9

The ubakus site allows you to try different build ups, although uses German products.

https://www.ubakus.de/

Of more a concern through would be ensuring moisture can get out of the wall. How old are the walls? Is there a damp proof course?

[Alan Ambrose]

FYI It’s easy to add your own materials to ubakhus if you need.

 

it also has some moisture calcs.

 

It’s useful with the expanses of flat walls / roof / floor with consistent make-up. But the thermal bridges at the ‘corners’ might also be important in an older building where they wouldn’t have been comsiderad originally.

Edited June 15 by Alan Ambrose

[lakelandfolk]

Thank you I will check it out