Good afternoon, Is there a rule of thumb for collar ties? We are having a room built with a vaulted ceiling. On the plans however there is no details for the height of the collar ties other than they need to be installed due to the vaulting. BCO has said put them at the height of the rest of the house ceilings which is just a ceiling………. and pointless. Roof is 40degree pitch Rafters are 2342mm plumb cut to birds mouth if that helps. thanks for any input.