Curtain Poles span and extra support

[50plusabit]

I have a set of french doors that go right up to the ceiling, I want to put a curtain pole up for curtains. They all have three pole supports and I do not have anywhere to put a middle support, as its just ceiling.
Does anybody know what the maximum span I can get away with just the two end supports?

 

[JohnD]

can't you see where the ceiling timbers are? with good light you may be able to see dust shading or nail marks, otherwise you can tap the ceiling with your knuckles.

Or you can just drill a few small holes and poke them to feel for the timber.

 

[Burnerman]

I think you'll definitely need the central support as heavy curtains will almost certainly cause a sag in the middle. Is it possible to fix the supports on the door frame, right at the top? If not, there's no guarantee that there will be a ceiling joist at dead centre to fix to - but you could maybe use a spring toggle fixing or perhaps a 'redidriva' type that screws directly into plasterboard.

 

[ColJack]

it depends on a lot of things..

how heavy are the curtains?
what is the pole made of?
how thick is the pole?

 

[foxhole]

Fix centre support to ceiling there should be a timber right at the edge for securing the ceiling plasterboard.

 

[eggbox]

I had the same problem, I spoke to Richard at simplycurtainpoles and he suggested a Rockingham pole as it has closed brackets. I had a joist directly above the window so fixing 3 brackets wasn't a problem.

My window width is 3 metres and that was not a problem with the three brackets.

Hope this helps!