Here the left hand door is the door opening first, this is known as the master door and this configuration would be know as left hand opening (L.H.O). If the right hand door opened first, this would be know as right hand opening (R.H.O). When making this decision please remember you are pulling to door open, not pushing it open.

FD30 Flushed Door

As there is no rebate, the position of the handle dictates which door is the leading door

An intumescent smoke seal are used on one side as it has a additional brush on the surface of the seal. As it will stop smoke, it will also help stop light and draft coming through the gap between the doors