Chimney breast removal - Want advice re Lintel

[zo]

I am just having my chimney breast removed. The lintels have arrived and I am surprised to see that it is a concrete beam with two thin metal strips inside the so called lintel. I thought lintels were alway made of iron/metal. Will the concrete beam be enough to support the chimney stack in the loft and the chimney/pots above the roof. I need advice now urgently as the builders are here. The guys removing the chimney breast is not sure how to do it, so is waiting for the guy employing them to show him how to do it. In the meantime, the worker has removed top half of the chimney in the upstairs room without any supports at all.

 

[tony1851]

Chimney stacks in the roof space are usually supported off a steel beam spanning between the load-bearing walls below, or - less adviseable - on metal brackets (aka gallows brackets) fixed immediately underneath.

Concrete lintels may not necessarily lend themselves to this type of work, but a pic or sketch would enable us to see the situation better.