According to the comprehensive answer no. 11494 regarding the length of the beard; it is Makrooh-e-Tahrimi if one trims his beard shorter than a fist’s length. My question is that what should a person do if the health of his beard-hair is not very good. Is it possible for him to trim his beard becuase about 90% of the hair have twin-heads, some hair even have around 5,6 heads. Also, the thickness of a single strand of hair is not uniform and because of this the hair is broken when combed resulting in uneven length of hair. It should be noted that if the length is kept short, these problems do not arise. Oils and other techniques have also been tried to keep the hair soft and thus not break or have twin-headas. In this case Would it be advisable to trim the beard to smaller than a fist’s length?
It is established from the Ahaadith that to keep a one fist long beard is Waajib. To trim it lesser than one fist length is sinful. (Nawadirul Fiqh vol.2 pg.356)
The reason you mention is not a valid excuse for trimming the beard lesser than a fist length.
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai