It's sapele. The door is primed, yet to be painted. He also just told me to caulk this gap above the left-hand panel which is 15mm deep. I'm worried about water ingress. This is the second door he's made, the first one the panels split within 3 months because he only biscuit jointed them. Do you think these panels will just split as well? South facing door, no porch, exposed to elements. Thanks for your time.