U value calculator for barn conversion

[Dansow]

Hi can anyone recommend a u value calculator for a insulated timber studding inside solid stone walls please?

[SteamyTea]

1 minute ago, Dansow said:

Hi can anyone recommend a u value calculator for a insulated timber studding inside solid stone walls please?

You really need to go back to first principles.

Find out the timber type (probably a pine), the lengths, probably 0.15 to 0.2m, and the total area that will be covered.

Then find the thermal conductivity of the timber, somewhere between 0.14 and 0.22 W.m^-1.K^-1 depending on grain orientation.

 

Then convert to a U-Value.

 

W.m^-2.K^-1 = 1 / (length / thermal conductivity).

 

[saveasteading]

1 hour ago, Dansow said:

a u value calculator for a insulated timber studding inside solid stone walls please?

It's really quite complicated but worth studying so that you can make the best decisions.

 

We have been converting a  farm building with 600mm stone walls, then a timber 'tent' inside. We have u values to match new-build. 

The stone wall has a decent figure itself, confirmed in studies, that the standard calculators wont acknowledge, so we diy-ed it. 

 

Or find any calculator and say the external wall is 1 brick (225mm) thick, and that will be  a start.

[SteamyTea]

 

[Dansow]

saveasteading What was your makeup inside?

Edited May 21, 2024 by Dansow

[JohnMo]

30 minutes ago, Dansow said:

saveasteading What was your makeup inside?

If you type @ and immediately after start typing sav... you will get name appear below, select from the drop down and the saveasteading will be notified of your reply 

[Alan Ambrose]

Ubakus.de

[saveasteading]

10 hours ago, Dansow said:

saveasteading What was your makeup inside?

@DansowI'm up on a mewp, surveying the next project  today. Will respond later.

[saveasteading]

@Dansow

600mm stone wall , 100 years old, (in 3 layers.)

nominally 25mm gap but varies dramatically.  so lets say minimum 50mm

timber stud wall with fancy vapour barrier on outer face and poly barrier on inner face, void filled with part rockwool and part pir.  or all pir. 2 layers is much easier and more accurate then 1.

25mm service gap. plasterboard.  optional additional insulation on the inner face to get any U value you want.

 

[Dansow]

@saveasteading Thank you

 

[CAJ]

Hi Dansow,

We put together a material summary and calculation guide and worked example for R-Values and U-Values on the page linked below:

https://www.insulationadvice.co.uk/ti-r-values

This should hopefully be of help!

[SteamyTea]

Once the U-value is established, then we can discuss condensation points.