Timber door frame fixing

[Brendan]

My garage has openings front and rear, and I already have timber side hinged doors with frames to go into the openings.

 

At the rear opening, there is brickwork either side of the opening for the timber frame to fix into and a Catnic lintel overhead.

 

How should I be fixing the timber frame to the Catnic lintel?

Edited July 12, 2023 by Brendan

[Dave Jones]

https://www.screwfix.com/c/screws-nails-fixings/self-drilling-screws/cat840204

 

[Brendan]

Thanks.