Lintel size

[Tony_Contata]

Hello,

I'm installing a window upstairs, standard loading, the house is victorian and the wall is solid around 250mm thick without plaster.

I'd like to use a smooth/cast stone lintel on the outside that can be painted to match the other windows.

So I'm thinking of using a Catnic Lintel CN71A @ 1200 long, but this is only 200mm deep.
Is it OK for the exterior head to over hang the edge of the lintel? Should I get the exterior head at 150mm deep?

Or is there a better solution for this?
I'd ask BC but they have been no use at all!

Thanks in advance

 

[^woody^]

No. Use an internal box or concrete lintel and an external tray lintel