NCC 2019 Volume 2 - 3.5.3.4 Installation of gutters (a)Gutters must be installed with a fall of not less than— (i)1:500 for eaves gutters, unless fixed to metal fascias; and (ii)1:100 for box gutters. (b)Eaves gutters must be— (i)supported by brackets securely fixed at stop ends and at not more than 1.2 m centres; and (ii)be capable of removing the overflow volume specified in Table 3.5.3.3a and Table 3.5.3.3b. (c)Overflow measures in accordance with Table 3.5.3.4a and Table 3.5.3.4b are deemed to be capable of removing the overflow volume specified in that Table. (d)Valley gutters on a roof with a pitch— (i)more than 12.5 degrees — must have width of not less than 400 mm and be wide enough to allow the roof covering to overhang not less than 150 mm each side of the gutter; or (ii)not more than 12.5 degrees — must be designed as a box gutter. (e)The requirement of (b)(ii) does not apply to eaves gutters fixed to a verandah or an eave that is greater than 450 mm in width, which— (i)has no lining; or (ii)is a raked verandah or a raked eave with a lining sloping away from the building.
