4.5 metres Bi-fold doors, how do I fix the top???

[catlad]

I fitted some recently and they were top hung, if yours are the same then brackets won't do, you will need to fix into the lintel.

 

[BobTheBear]

Cheers oldun, so I can drill through the lintel then?

Above the outer lintel there is blockwork and drilling through the frame, though the lintel and into the blockwork with some fisher fixings would be the easiest route

 

[theoldun]

Yes. Although the top fixing straps are more important as they hold the frame tight to plaster when opening doors.
Modern bifold doors do not put any downward pressure on head of frame, but work on the principle of the weight being supported from door hinge to door hinge plus additional support from bottom rollers.
Top rollers act as a guide., that is why top wheels are normally nylon and bottom wheels steel.
Regards oldun

 

[^woody^]

Errr, some systems are top hung and the head and wheels take the load not the hinges

 

[sandy10]

Most systems are bottom running, with top guides, which reverse when the doors go over a certain height parameter.

If you can advise on the system you propose to fit, I can offer a fitting guide.