On 10/03/2020 13:38, Bert Coules wrote:
Is there a way of establishing the structure and integrity of a block
wall without removing the covering plaster?Â* X-rays?Â* Some other techy
wizardry?

Thanks.

An IR camera works - different thermal characteristics of the morter v
the blocks.
I discovered this accidentally after lookingat the ceiling for cold
spots in my loft insulation and pointed at the walls when the block and
morter showed up very clearly.