Hi all, a custard wants to add 4 radiators to there existing system and is like to get the pipe work in before the boards go up. I was just gonna run a 10mm manifold off the 22mm flow/return and that gives me the 4 flow and returns for the rads does this seem like the best practice? It's an extension at the back of the house and all 4 rads are going in there and the out house. Any suggestions please?