I heard a hadith preventing from folding the pants/lower garment. I fold them all the times and not only in Salat does that also comes in the purview of that hadith.
Al-jawab billahi at-taufeeq (the answer with Allah's guidance)
According to our knowledge there are no such reports like this.
It is Haram and sinful to have one's garment, lower garment etc, below the ankles.
It is narrated by Mughirah Ibn Shu'bah that Prophet (Sallallahu Alaihi Wasallam) said,"O Sufyan Ibn Sahl! Do not do Isbaal (letting the garment fall below the ankles), because Allah does not like the one who let their garment fall below the ankles. (Nasai')
Please refer to: http://www.muftisays.com/qa.php?viewpage=viewQA&question=3120
(See: Fiqhi Jawahir Vol. 2, By Mufti Faruq Sahib Damat Barakatuhum)