Hi thanks for your help so far. I have drawn a scale drawing of what i think my installation might look like. do you think this would work? are the cedral click boards made of something that i can router? are they made from a carcinogenic material at all? Please see the attached picture and ask any questions you like. So the part in question is the cedral board that i have coloured yellow, i am thinking that if i set the batten slightly back from the face nearest the french door (by about 6mm) then that will give me enough room to have a reveal, that would mean though that i would need to router the back of the cedral lap slightly so it fits in the gap. Do you think this would be possible. I dont think i would be able to instal the corner profile before i put the reveal board in but i could use color coded nails to fix the reveal and corner profile on that side and then fix it normally on the front.
Thanks again