U (or R) value of a 100 mm Thermalite Block

[LeanTwo]

Not being of a technical nature my research into the U value (or its reciprocal the "R" value,  I understand) has frustrated me!  Can anyone tell me the U value of a 100 mm Thermalite block, please?  Is there a handy table somewhere?

 

Many thanks.

[ToughButterCup]

The manufacturers will have a downloadable data sheet.

[A_L]

1 hour ago, LeanTwo said:

Can anyone tell me the U value of a 100 mm Thermalite block, please?

 

Only complete walls have a 'U-value', what you need is the thermal conductivity, W/m.K from which you calculate the thermal resistance or R-value for each component.

 

R=thickness in mm/(thermal conductivity*1000)

 

Then add all the R-values together and invert to get the U-value.

 

Here is the data for thermalite turbo block https://www.forterra.co.uk/plugins/downloads/files/Thermalite_Turbo_datasheet_1.pdf

 

N.B. This is only for above dpc applications, thermal conductivities below dpc are much higher, typically 0.25W/m.K

 

[Jilly]

I got worried about this too.  When you have full plans Building Control application, it is all worked out by the architect's technician, double checked by BC themselves and then further number crunched by someone who does the SAP calculations, so you don't need to worry too much, other than having an idea.