Hope someone can help with this. I’m half way through making some sapele gates for the side of my house. Frames are all put together and now it’s time to board them up with v-notched t&g boards (in sapele). Boards are to run vertically and there will be ten on each gate, approx. 85mm wide. The sapele has been air dried to around 15-20%. I’m just wondering how much gap would be advisable to allow for expansion on each side of the board?