Mount 6mm ceiling panels along or across battens?

[Olaf3]

I am planning to install a 6 mm MDF ceiling with a width of 390 mm per board in a small room, under 10 m2, and there are 45x70 beams across with c/c 300. The manufacturer of the ceiling advises installing beams along with the boards' c/c and nailing at c/c 150.

It's not difficult to read what the manufacturer writes, but they are being cautious, and my question is if anyone has installed similar boards with nails at c/c 300 and experienced sagging between the attachments?

 

[SBH]

think about the nails you place, they should support two boards.
and you will be nailing (the nails have very small heads)
place them at c/c150. very little price difference

 

[Olaf3]

Ok, good comment about it holding two boards per nail, so now I have installed longitudinal battens at c/c 390.

 

[SBH]

Ok, good comment about it holding two boards per nail, so now I have fixed down longitudinal battens at c/c 390

no, the nails should hold for two boards. So don't skimp on the nails.