lintel size. help needed please

[redbarron1]

i have replaced a set of garage doors with a set of french doors whilst converting my garage. The upvc doors are 2400 wide. I intend to put a concrete lintel over the top 2800 long. the door is currently fixed into a single skinned wall. To get to the roof (which the wall and lintel will not be supporting) I need to lay 5 courses of bricks on top of the lintel. Can anyone tell me the height of the lintel i need if i use a 70mm prestressed concrete lintel.

Many thanks

Update !!!!! My Dad says to use timber and stud the gap above. Then clad it with tiles or something. He says it will be Less weight so no lintel needed, far cheaper and easier to construct. Does that sound Right to any DIY experts out there.

Many Thanks

 

[bookahandyman]

if the door and frame is not supporting anything above it , then your dad is right yo can just stud it and insulate, then tile or plastic clad. if you wanted to brick it up you would need a single skin catnick lintle made of steel not concrete, a concrete one would probably break at that length if yo could find one. the likes of travis perkins will do them or even b&q if you have a warehouse store near you, but they are not cheap , around £100 probably.