▁ 2 4   in ches ▁on ▁center , ▁with ▁spacing ▁variations ▁lower ▁and ▁higher ▁depending ▁upon ▁the ▁loads ▁and ▁cover ings . ▁ ▁Wall ▁members ▁are ▁typically ▁vertical ▁li pped ▁channel ▁“ stud ” ▁members , ▁which ▁fit ▁into ▁un li pped ▁channel ▁“ track ” ▁sections ▁at ▁the ▁top ▁and ▁bottom . ▁ ▁Similar ▁configurations ▁are ▁used ▁for ▁both ▁floor ▁jo ist ▁and ▁ra fter ▁assemb lies , ▁but ▁in ▁a ▁horizontal ▁application ▁for ▁flo ors , ▁and ▁a ▁horizontal ▁or ▁s loped ▁application ▁for ▁roof ▁fr aming . ▁ ▁Add itional ▁elements ▁of ▁the ▁fr aming ▁system ▁include ▁fast en ers ▁and ▁connect ors , ▁bra ces ▁and ▁b rac ing , ▁cli ps ▁and ▁connect ors . ▁ ▁In ▁North ▁America , ▁member ▁types ▁have ▁been ▁divided ▁into ▁five ▁major ▁categories , ▁and ▁product ▁nom en cl ature ▁is ▁based ▁on ▁those ▁categories . ▁▁ ▁S ▁members ▁are ▁li pped ▁channels , ▁most ▁often ▁used ▁for ▁wall ▁stud s , ▁floor ▁jo ists , ▁and ▁ce iling ▁or ▁roof ▁ra fter s . ▁ ▁T ▁members ▁are ▁un li pped ▁channels , ▁which ▁are ▁used ▁for ▁top ▁and ▁bottom ▁pl ates ▁( tra cks ) ▁in ▁walls , ▁and ▁rim ▁jo ists ▁in ▁floor ▁systems . ▁ ▁Tra cks ▁also ▁form ▁the ▁heads ▁and ▁s ills ▁of ▁windows , ▁and ▁typically ▁cap ▁the ▁top ▁and ▁bottom ▁of ▁box ed - ▁or ▁back - to - back ▁headers . ▁ ▁U ▁members ▁are ▁un li pped ▁channels ▁that ▁have ▁a