Guttering is generally sold in 2m or 4m lengths and is easily cut to size with a hacksaw but be sure to de burr any cut surfaces with a file or sandpaper.
Fitting internal gutter brackets.
It s easier to start by clipping in the back first.
Calculate minimum gutter fall of 1 50 that is for 2mm of fall for each metre of gutter then put a nail at the lower end and fix a stringline between the nails and check fall with a spirit level.
Take the first length and clip it into the running outlet then into the facia board brackets.
Having fitted the gutter brackets it is time to fit the guttering.
If you live in an area that is prone to regular heavy snowfalls position fascia brackets so they are no more than 400mm apart.