Mulling over how best to joint some long lengths of cill to minimise the inevitable shrinkage and subsequent water ingress.
A - simplest. Butt joint. Worst from water ingress. No resistance against lateral movement
B - better. Screws can go through to hold the joint. No resistance against lateral movement
C - best. Screws can go through to hold the joint. Resistance against lateral movement
Welcome to hear people's thoughts