@RichardHenry thank you for all that information!
This thread helps explain something I have puzzled about.
When we bought an apartment in Istanbul last year, the sellers explained that their family construction business had built the structure. They knew that the sand used was very high quality. This was a selling point as Istanbul sits on a fault line and earthquakes are a major concern.
But because I am ignorant about building construction I did not understand how quality of sand made a difference nor did I even understand what good quality meant for sand.
By the way, if anyone knows anyone here in Türkiye especially near Istanbul who are into urban permaculture please let me know.
Thank you!
