Thermalites to medium dense

[Geo57]

Hi all

My architect specified 3.6n thermalites (internal wall), together with 90mm near full fill in a 100mm cavity to be able to get a total 300mm cavity and meet the 0.18 requirement for cavity walls

However my SE has mentioned that I will need medium dense blocks as needs to support a steel ridge

U value calculators bring this in at 0.19 (using medium dense, 90mm near full fill & outer facing brick work)

Am I going to need to amend my building regs application to go for a larger cavity, or could I increase the insulation in other areas to mitigate this (ceiling for example?)

Thanks
Geo

 

[stevie888]

Get your SE to do his job and spec a padstone to suit the blocks the steel has to sit on