3x2 ceiling joists

[Doogal37]

I‘ve removed the old fibreboard from our bedroom ceiling and now need to level out the joists before putting the plasterboard up.

the joists are showing roughly 2.5 metres across, but clearly extend beyond this room, and are 3x2 apart from the main supporting one, which is 4x2.

I aim to counter batten the room to level the very un-level joists ready for the plasterboard.
Are the 3x2 capable of holding this and also the plasterboard and also a layer of skim?

they’re in good shape, but I only see 4x2 joists mentioned on ceiling and plastering threads, no mention of 3x2.

 

[jamesr36]

If it is a loft above that you might access and store stuff the max span for 3x2 is only about 1.5m. If the space above is not accessible and is only holding itself and the ceiling up it should be okay.

That is the engineers answer but I suppose battens and plasterboard are not that much heavier than a sheet of fibreboard so if it survived the last 20 years it will probably be okay. Just don’t store stuff above it

 

[Doogal37]

Thanks for the reply - there’s no storage on these, so just the plasterboard and wood per sq ft.

 

[fenny666]

I don't think you need to worry especially as you've removed the existing. Weight wise I'd hazard that what you've removed won't be a million miles away from what you're replacing it with. It's likely also the joists far exceed the original fibreboards bearing. It's an assumption though, but based on common sense, it's what you would expect?
One important thing to note is joist centres determine board thickness. 12.5mm can be used up to a max 450mm. Above that 15mm to max 600mm centres.