Wind-post or no wind-post

[SKD_BW]

Morning guys.

I am looking into a small single story extension (2.1m projection for the existing rear elevation) and I am wondering if there is a calculation I can do to check if a wind post is required.

The new lean to extension will have a 750mm return which will act as a buttress, but the distance between the lateral buttress will increase from 3.5m to 5.6m.

I would like to have a flush wall, so it will either need to be a column built into the internal skin or a padstone sat on the existing brickwork. Obviously, a padstone is the preference - but I would like to check if a wind-post is required by doing a mathematical calculation and not leaving this decision to discretion the building inspector (as every building inspector in the area seems to have a different opinion on this or sometimes just say "SE to confirm").

Sketch of the existing and proposed layouts below. Thanks in advance for your help!

 

[GeorgeTheCivilEngineer]

Hello - you are best off contacting a local structural engineer to determine this.

 

[SKD_BW]

Thanks George - I spoke with one of my colleagues and the assessment I was looking for is the "assessment laterally loaded masonry panels" and there is guidance on this in BS 5628 which has been superseded by Eurocode 6.

I have done an initial assessment and it is quite apparent that a wind post will be required, which I expected for this project, however it is always good to have some 'numbers' to back up a 'gut-feel'. Moving forward I will be interested to see how the assessment looks for smaller openings.

Just thought I would let you know incase anyone else comes across this thread in the future and is looking for some guidance.