Backblocking Ceiling?

[memphis]

Ive recently had my 2nd story addition sheeted with gyprock, the ceiling has sheets running across the battens (not parallel), but when i was in the ceiling i noticed it wasnt back blocked, is this an issue?

They have only blocked the butt joins...

My roof is steel with steel battens at 600 centres.

I will post a photo tonight when I get home, im looking to plaster the lot on wednesday so if they need to be backblocked I would need to do it before then.

thanks!

[memphis]

Correction, they are screwed off at 450 centres, not 600

[addo]

Backblocking in this case, would normally be done only on the butt joins - as you've noted. If there were other factors like high humidity or fire control, it could be different.