Hello, I want to remove chimney breasts from my semi-detached houses in two phases, leaving stack in place. Fortunately I own both of the semi-detached house, so no problem with party wall, and negotiation with neighbour. I understand that gallows bracket is a common practice to support remaining stack. However, it shall create problem when I get the same job done on the other half. What are my options in terms of structural support if I get the job done in two phases and in one phase? Any cost benefit, if I get the support part done in one phase? Thank you.