Reply To: Mechitza at weddings

Rav Yosef Chaim Sonnenfeld (amongst others) held that mechitzos are required at weddings.

http://hebrewbooks.org/pdfpager.aspx?req=46247&st=&pgnum=192

http://hebrewbooks.org/pdfpager.aspx?req=46247&st=&pgnum=193

http://hebrewbooks.org/pdfpager.aspx?req=1884&st=&pgnum=267