weep holes

I get the nature of a weep hole and it’s function. Are there any standards other than one every 36 "? Like the cavity it serves or more for instance?

Cheers Lee.

These pdf’s should help explain weeps.

http://www.gobrick.com/Portals/25/do…0Notes/TN7.pdf

http://www.mtidry.com/news/articles2…m_medium=email