DPC For Patio Doors Lintel In Solid Brick Wall?

Hi,

A bit of urgent advice required!

I am in the process of removing a window and putting in patio doors (i have had to widen the opening. I have an rsj lintel for the outside and a heavy duty catnic lintel for the inside (just because these were available to me for free).

It is a solid Victorian brick wall. Do i need some sort of DPC above one or both of the lintels? The only diagrams i see are for cavity walls. The eaves of the house overhangs by about 400mm so the wall does not get too wet and i am about the have this wall re-rendered.

If i do need one - how do i fit it? I have already installed the internal catic lintel but can take it back out if necessary.

Is this only required on cavity walls because in that case you would be bridging the external to internal wall?

Maybe i just need some strip along the top and bottom of the rsj to protect the rsj itself from moisture??