S
sambotc
We've always gone by 250mm, sometimes pushed it too 300mm if i'm honest because its a mare getting a noggin in (right down in the eaves for example) but even 300mm allows a lot of play up and down, normally try and keep them as close as possible to the edge. Over time that movement will definitely have an effect on the fixings becoming loose in my opinion quite a bit of leverage there putting strain on the end roof hook.